Journal articles: 'AZ91D'

1

Melnikov, Evgenii S., Maria A. Surmeneva, Alexander I. Tyurin, Tatyana S. Pirozhkova, Ivan A. Shuvarin, Oleg Prymak, Matthias Epple, and Roman A. Surmenev. "Improvement of the Mechanical Properties of AZ91D Magnesium Alloys by Deposition of Thin Hydroxyapatite Film." Nano Hybrids and Composites 13 (January 2017): 355–61. http://dx.doi.org/10.4028/www.scientific.net/nhc.13.355.

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Structural and mechanical behavior of thin hydroxyapatite (HA) films deposited via radio-frequency magnetron sputtering on AZ91D magnesium alloy was investigated. Nanoindentationwas employed to evaluate nanohardness and Young’s modulus of the uncoated and HA-coated AZ91 magnesium alloy. The HA-coated AZ91D magnesium alloy exhibited a higher hardness of 7.1 GPa and a higher modulus of 86 GPa compared withthe uncoated substrate revealing a strong load-bearing capacity.

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Shkurankov, Andrey, Sherif Zein El Abedin, and Frank Endres. "AFM-Assisted Investigation of the Corrosion Behaviour of Magnesium and AZ91 Alloys in an Ionic Liquid with Varying Water Content." Australian Journal of Chemistry 60, no. 1 (2007): 35. http://dx.doi.org/10.1071/ch06305.

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Atomic force microscopy (AFM)-assisted corrosion measurements of poly- and microcrystalline magnesium, of AZ91D magnesium alloys, and of AZ91D alloys with defined amounts of metallic impurities (Cu, Ni, and Si) in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethylsulfonate with variable water contents is reported. Whereas both magnesium and the AZ91 alloys show a tremendous corrosion in aqueous solutions, they are practically inert in the water-free ionic liquid. The apparent electrochemical window of the water-free ionic liquid on magnesium and its alloys can reach values of 10 V and more. The low corrosion rate of AZ91 alloys with metallic impurities, in any case, follows the trend in aqueous solutions: in comparison to the base alloy, the addition of nickel and silicon leads to higher corrosion rates. Upon addition of water to the ionic liquid two effects are observed. The higher the water content in the ionic liquid, the lower the corrosion potential and the higher the corrosion rate. Poly- and microcrystalline magnesium shows a surprisingly complicated corrosion behaviour, which gives rise to different processes during electrochemical polarization. As a proof-of-principle, in-situ AFM measurements were performed on the corrosion of AZ91D alloy in the ionic liquid. No corrosion products are observed at the surface in the water-free ionic liquid by in-situ AFM, even after several hours at +3 V versus a saturated calomel electrode (SCE), which indicates surface passivation in the ionic liquid.

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Ming, Yuan, Yu Sirong, Liu Enyang, Li Fanguo, Zhao Yan, Zhang Shanbao, and Li Jingda. "High-temperature damping capacity of fly ash cenosphere/AZ91D Mg alloy composites." Science and Engineering of Composite Materials 25, no. 1 (January 26, 2018): 197–204. http://dx.doi.org/10.1515/secm-2016-0094.

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AbstractIn this study, fly ash cenospheres were added to semisolid AZ91D Mg alloy to prepare fly ash cenosphere/AZ91D (FAC/AZ91D) composites by means of compo-casting. The high-temperature damping capacity of FAC/AZ91D composites was investigated as compared with AZ91D Mg alloy. The results show that the damping capacities of FAC/AZ91D composites and AZ91D Mg alloy strongly depend on the measuring temperature. The FAC/AZ91D composites show better damping capacity than AZ91D Mg alloy. The 10 wt.% FAC/AZ91D composites exhibit the best damping capacity from room temperature to 125°C, whereas the 2 wt.% FAC/AZ91D composites show the highest damping capacity at 125°C–320°C. The damping mechanism was analyzed by microstructure observation at elevated temperatures. The damping-temperature curves exhibit a damping peak at approximately 150°C, and the activation energy of the damping peak was calculated according to the Arrhenius equation. Furthermore, the peak temperature increases with increasing frequencies. The damping peak is related to the thermal activation relaxation process, and its mechanism is the dislocation-induced damping.

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Jia, Suqiu, Shu Sheng Jia, Guangping Sun, and Jun Yao. "The Corrosion Behaviour of Mg Alloy AZ91D/TiCp Metal Matrix Composite." Materials Science Forum 488-489 (July 2005): 705–8. http://dx.doi.org/10.4028/www.scientific.net/msf.488-489.705.

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The corrosion of a magnesium-based MMC, comprising a AZ91D alloy matrix and 5 vol% titanium carbide particles has been studied in saline environments, using immersion and electrochemical tests. Corrosion was localized initially and developed subsequently into general corrosion , the local corrosion rate of AZ91D/TiCp being faster than diecast AZ91D due to the formation of less protective corrosion products. Galvanic corrosion for AZ91D/TiCp, due to coupling of the matrix and reinforcement, was more severe than diecast AZ91D.

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Hu, Xiao Shi, Kun Wu, Ming Yi Zheng, Shi Wei Xu, and Y. K. Zhang. "Effect of Deformation on the Damping Capacity of Magnesium Alloys." Materials Science Forum 488-489 (July 2005): 737–40. http://dx.doi.org/10.4028/www.scientific.net/msf.488-489.737.

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Equal channel angular extrusion (ECAE) was applied to an as-cast AZ91D magnesium alloy. The strain amplitude dependence and temperature dependence of damping capacities of the as-cast and ECAE processed AZ91D alloys were investigated by dynamic mechanical analyzer (DMA). Microstructures of AZ91D alloys after ECAE were observed by optical microscopy (OM). In higher strain region, the damping value of 4-pass ECAE deformed AZ91D alloy was the highest among all the AZ91D alloys under different conditions. The damping peaks of ECAE deformed AZ91D alloys detected during heating from room temperature to 400°C were considered to be related to the migration of grain boundaries and the movement of dislocations during recrystallization.

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ZHANG, X. P., Y. S. ZOU, F. M. WU, Z. P. ZHAO, L. YOU, C. F. GU, and Y. Z. LIAO. "WEAR RESISTANCE OF AZ91D MAGNESIUM ALLOY WITH AND WITHOUT MICROARC OXIDATION COATING AND Ti6Al4V ALLOY IN ARTIFICIAL SALIVA." Surface Review and Letters 16, no. 06 (December 2009): 821–30. http://dx.doi.org/10.1142/s0218625x09013372.

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The wear resistances of AZ91D magnesium alloy with and without microarc oxidation (MAO) coating and Ti 6 Al 4 V alloy in artificial saliva were investigated at room temperature. The wear resistance of AZ91D magnesium alloy in artificial saliva was significantly improved after microarc oxidation treatment. The volume loss of untreated AZ91D magnesium alloy sample was 20.95 times of that of AZ91D magnesium alloy with MAO coating, and that of Ti 6 Al 4 V was 5.42 times of that of MAO. Furthermore, the wear resistance of AZ91D magnesium alloy was lower than that of Ti 6 Al 4 V alloy in artificial saliva. The wear mechanisms of AZ91D magnesium and Ti 6 Al 4 V were discussed. It was found that the wear mechanism of the MAO was associated with abrasion and microfracture. There were two dominative wear mechanisms for AZ91D alloy and Ti 6 Al 4 V alloy under the loading conditions used in the experiment, namely, micro-machining wear and deformation-induced wear.

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7

Cheng, Jun, Jian-hua Zhao, Jin-yong Zhang, Yu Guo, Ke He, Jing-Jing Shang-guan, and Fu-lin Wen. "Microstructure and Mechanical Properties of Galvanized-45 Steel/AZ91D Bimetallic Material by Liquid-Solid Compound Casting." Materials 12, no. 10 (May 21, 2019): 1651. http://dx.doi.org/10.3390/ma12101651.

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A connection between hot-dip galvanized 45 steel and AZ91D was achieved by liquid-solid compound casting to achieve one material with a better mechanical performance and a light weight. The microstructure and properties of galvanized-steel/AZ91D bimetallic materials were investigated in this study. A scanning electron microscopy (SEM), an energy dispersive spectroscopy (EDS), and an X-ray diffraction (XRD) were applied to analyze the microstructure evolution and formation mechanism of the galvanized 45 steel/AZ91D interface zone which could be divided into three layers. Among three different layers, the layer close to AZ91D was composed of α-Mg and an eutectic structure (α-Mg + MgZn). The intermediate layer was comprised of an eutectic structure (α-Mg + MgZn), and the layer adjacent to 45 steel consisted of α-Mg and FeAl3. Furthermore, galvanized-45 steel/AZ91D bimetallic material had better shear strength than the bare-45 steel/AZ91D metallic material which can indicate that owing to the formation of metallurgical bonding, the adhesive strength of galvanized-steel and AZ91D was improved to 11.81 MPa. In addition, the fact that corrosion potential increased from −1.493 V to −1.143 V and corrosion current density changed from 3.015 × 10−5 A/cm2 to 1.34 × 10−7 A/cm2 implied that the corrosion resistance of galvanized-steel/AZ91D was much better than AZ91D.

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8

Fahad, Mohammed, and Bavanish B. "Tribological behavior of AZ91D magnesium alloy composite: effect of hybrid WC – SiO2 nanoparticles." Industrial Lubrication and Tribology 73, no. 5 (July 14, 2021): 789–95. http://dx.doi.org/10.1108/ilt-02-2021-0038.

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Purpose Aviation field requires a material with greater tribological characteristics to withstand the critical climate conditions. Hence, it is of paramount importance to enhance the wear resistance of material. AZ91D magnesium alloy is a light weight material used in the aviation field for the construction work. The purpose of this study is to augment the wear properties of AZ91D alloy by reinforcing with hard particles such as tungsten carbide (WC) and silicon dioxide (SiO2). Design/methodology/approach In this work, three types of composites were fabricated, namely, AZ91D – WC, AZ91D – SiO2 and AZ91D – (WC + SiO2) by ball milling method, and the tribological properties were analyzed using pin-on-disc apparatus. Findings Results showed that the hardness of AZ91D alloy was greatly improved due to the reinforcing effects of WC and SiO2 particles. Wear study showed that wear rate of AZ91D alloy and its composites increased with the increase of applied load due to ploughing effect and decreased with the increase of sliding speed owing to the formation of lubricating tribolayer. Further, the AZ91D – (WC + SiO2) composite exhibited the lower wear rate of 0.0017 mm3/m and minimum coefficient of friction of 0.33 at a load of 10 N and a sliding speed of 150 mm/s due to the inclusion of hybrid WC and SiO2 particles. Hence, the proposed AZ91D – (WC + SiO2) composite could be a suitable candidate to be used in the aviation applications. Originality/value This work is original which deals with the effect of hybrid particles, i.e. WC and SiO2 on the wear performance of the AZ91D magnesium alloy composites. The literature review showed that none of the studies focused on the reinforcement of AZ91D alloy by the combination of carbide and metal oxide particles as used in this investigation.

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Lin, Bi Lan, Yu Ye Xu, and En Cai Li. "Effect of Phosphating Additives on Corrosion Resistance of Phosphate Coatings on AZ91D Magnesium Alloy." Advanced Materials Research 337 (September 2011): 112–15. http://dx.doi.org/10.4028/www.scientific.net/amr.337.112.

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AZ91D magnesium alloys were immersed in different phosphating solutions with zinc nitrate and sodium fluoride additives to enhance the corrosion resistance. The devolution law of the Open Circuit Potential (OCP) of AZ91D alloys during phosphating was measured. The corrosion behaviors of AZ91D alloys in 3.5%NaCl solution were investigated using OCP and Tafel polarization methods, and the effect of phosphating additives was discussed. The results show that the changes of the OCP of AZ91D alloys with phosphating time in different phosphating solutions are different; the anodic and cathodic corrosion processes of AZ91D alloys are conspicuously inhibited with phosphate coatings; zinc nitrate and sodium fluoride are benefit to form phosphate coatings with better corrosion resistance. The corrosion potential of AZ91D alloy phosphated in solutions with both zinc nitrate and sodium fluoride is most positive.

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10

Wang, Yingying, Bernard Normand, Xinkun Suo, Marie-Pierre Planche, Hanlin Liao, and Junlei Tang. "Cold-Sprayed AZ91D Coating and SiC/AZ91D Composite Coatings." Coatings 8, no. 4 (March 26, 2018): 122. http://dx.doi.org/10.3390/coatings8040122.

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11

Tian, Jun. "Effect of Fiber Volume Fraction on High Temperature Creep of Al₂O₃-SiO₂(sf)/AZ91D Composite." Key Engineering Materials 474-476 (April 2011): 548–52. http://dx.doi.org/10.4028/www.scientific.net/kem.474-476.548.

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Constant stress tensile creep tests were conducted on AZ91D–20 vol.%, 25 vol.%, and 30 vol.% Al2O3-SiO2short fiber composites and on an unreinforced AZ91D matrix alloy. The creep resistance of the reinforced materials is shown to be considerably improved compared with the matrix alloy. With the increasing volume fraction of short fibers, the creep resistance of AZ91D composites is improved, and their creep threshold stresses are also increased accordingly. Because of the increasing volume fraction of short fibers, loads of bearing and transmission of short fibers will increase, and thus the creep resistance of AZ91D composites further improves, but the precipitation of β-Mg17Al12precipitate increases in the number, it is easy to soften coarse, so that threshold stress of AZ91D composite does not increase greatly.

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12

Huang, Kaijin, Lin Chen, Xin Lin, Haisong Huang, Shihao Tang, and Feilong Du. "Wear and Corrosion Resistance of Al0.5CoCrCuFeNi High-Entropy Alloy Coating Deposited on AZ91D Magnesium Alloy by Laser Cladding." Entropy 20, no. 12 (November 30, 2018): 915. http://dx.doi.org/10.3390/e20120915.

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In order to improve the wear and corrosion resistance of an AZ91D magnesium alloy substrate, an Al0.5CoCrCuFeNi high-entropy alloy coating was successfully prepared on an AZ91D magnesium alloy surface by laser cladding using mixed elemental powders. Optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction were used to characterize the microstructure of the coating. The wear resistance and corrosion resistance of the coating were evaluated by dry sliding wear and potentiodynamic polarization curve test methods, respectively. The results show that the coating was composed of a simple FCC solid solution phase with a microhardness about 3.7 times higher than that of the AZ91D matrix and even higher than that of the same high-entropy alloy prepared by an arc melting method. The coating had better wear resistance than the AZ91D matrix, and the wear rate was about 2.5 times lower than that of the AZ91D matrix. Moreover, the main wear mechanisms of the coating and the AZ91D matrix were different. The former was abrasive wear and the latter was adhesive wear. The corrosion resistance of the coating was also better than that of the AZ91D matrix because the corrosion potential of the former was more positive and the corrosion current was smaller.

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Wang, Xiao Ying, Yu Tao Zhao, Gang Chen, Song Li Zhang, and Xiao Nong Cheng. "In Situ Fabrication and Properties of Mg₂Si/AZ91D Magnesium Matrix Composites." Advanced Materials Research 150-151 (October 2010): 1640–43. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.1640.

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Mg2Si/AZ91D magnesium matrix composites are fabricated from AZ91D-Al2(SiO3)3 system by direct melt reaction method. The effects of the variation Al2(SiO3)3 addition contents to the microstructures and mechanical properties of the composites are investigated. The results show that the amounts of Mg2Si particles are increased and the structures of AZ91D magnesium alloy are refined with the Al2(SiO3)3 content increasing. When the additional content of Al2(SiO3)3 is 3wt.%, the tensile strength of the composite reaches 178.6MPa, which is increased by nearly 14.5% than that of AZ91D matrix alloy.

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Yuan, Jia Wei, Xing Gang Li, Kui Zhang, Yong Jun Li, Ming Long Ma, Guo Liang Shi, and Meng Li. "The Effect of Mixed RE Elements on Microstructure and Mechanical Properties of Die-Cast AZ91D Alloy." Advanced Materials Research 941-944 (June 2014): 59–65. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.59.

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The effect of mixed RE elements (Y, Nd, Gd ) on the microstructure and tensile properties of die-cast AZ91D alloy were investigated. The results indicated that the content of mixed RE elements lead to the change of the formation of Al▔RE compounds and reduction of the fraction of β-Mg17Al12 phase. The grain size of the alloy added 1.0wt. % RE became smaller than die-cast AZ91D and AZ91D+2.0wt. % RE alloys. The UTS of die-cast AZ91D+xRE(x=0 wt. %, 1.0wt. %, 2.0 wt. %) alloys were 204MPa, 194MPa, 203.6MPa at room temperature, respectively. Moreover, RE addition resulted in fracture behaviors changed.

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15

Lee, Du Hyung, Bo Sik Kim, and Si Young Chang. "Tensile Properties of AZ91D Magnesium Alloy Coated by Plasma Electrolytic Oxidation." Materials Science Forum 620-622 (April 2009): 259–62. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.259.

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Tensile properties of AZ91D magnesium alloy coated by Plasma Electrolytic Oxidation method for various coating times were investigated. The coatings on AZ91D magnesium alloy showed porous microstructure, and became thicker with increasing the coating time. After tensile test, the coated AZ91D magnesium alloy had lower tensile strength and elongation than the uncoated one. The tensile strength and elongation decreased with increasing the coating time, while the proof stress was almost no changed. The uncoated AZ91D magnesium alloy revealed ductile fracture surface. As the coating time increased, however, the fracture surface was changed to brittle fracture morphologies.

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Tang, Bin, Shuang Shou Li, Man Qiong Xu, and Da Ben Zeng. "Effects of Ca Addition into AZ91D Alloy on Structure and Tensile Fracture Behavior." Applied Mechanics and Materials 79 (July 2011): 25–28. http://dx.doi.org/10.4028/www.scientific.net/amm.79.25.

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The influences of Ca addition (<1.2wt %) on structure and tensile fracture behavior of AZ91D alloy were investigated in this article. These results indicated that Ca addition can both form Al2Ca phase on interdendritic boundary and refine grain size. Ca addition evidently increases the yield strength but decreases the elongation of AZ91D alloy. The crack initiations of the AZ91D alloy and Ca-contained alloy both occur at the edges between the interdendritic eutectics and the α-Mg matrix. Failure of AZ91D alloy is brittle quasi-cleavage fracture, while Ca addition makes the failure tend to be cleavage.

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Fan, Yu, Guo Hua Wu, and Chun Quan Zhai. "Effect of Strontium on Mechanical Properties and Corrosion Resistance of AZ91D." Materials Science Forum 546-549 (May 2007): 567–70. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.567.

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With adding 2% strontium in AZ91D, the ultimate tensile strength and the elongation increased by 10.3% and 55.3%, respectively. This is mainly caused by the refinement of the β phase and the formation of Al4Sr strengthening phase. Furthermore, with adding 2% strontium in AZ91D alloy, the weight loss corrosion rate in 5wt.% NaCl solution decreases to 0.048 mg·cm-2·d-1, which was 33.8 % of the AZ91D corrosion rate. Therefore, the mechanical properties and corrosion resistance of AZ91D could be improved by the addition of 2% strontium, which is due to the refinement of Mg17Al12 phase and the formation of Al4Sr phase.

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Ding, Jian, Lin Qin, Yong Yan Li, and Wei Min Zhao. "Effect of Nd and Dy Addition on AZ91D Ignition Temperature and Microhardness." Materials Science Forum 788 (April 2014): 34–40. http://dx.doi.org/10.4028/www.scientific.net/msf.788.34.

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Magnesium alloys are very active and readily ignite during heating and melting. In this study, the ignition-proof property of AZ91D with Nd and Dy addition was discussed, and the effects of these ignition-proof elements on the microstructure and microhardness of AZ91D investigated. The results show that the ignition-proof performance of magnesium alloy is improved obviously. The ignition resistance is attributed to the compact oxide films, which consist of MgO, Al2O3, Nd2O3, Dy2O3. When Dy content increased beyond 0.5%, the change tendency of ignition point of the alloy follows the shape of “v” curve, and the ignition point increased with Nd addition. The optimum composition of the newly developed magnesium alloy is AZ91D-3Nd-0.5Dy with the ignition point about 60K higher than AZ91D. And also AZ91D-3Nd-0.5Dy has fine microstructure and higher microhardness.

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Wang, Shun Cheng, Zheng Hua Huang, Wen Jun Qi, and Kai Hong Zheng. "Effect of Al-5Zr-1.1B Grain Refiner on Microstructure and Mechanical Properties of AZ91D Magnesium Alloy." Materials Science Forum 816 (April 2015): 337–42. http://dx.doi.org/10.4028/www.scientific.net/msf.816.337.

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An Al-5Zr-1.1B grain refiner was prepared by in-situ synthesis from Al melt and K2ZrF4+KBF4 mixed powder. The microstructure of Al-5Zr-1.1B grain refiner was analyzed by XRD, SEM and EDS. The effect of Al-5Zr-1.1B grain refiner on the microstructure and mechanical properties of AZ91D magnesium alloy were studied. Results show that a large number of fine ZrB2 particles were observed in the Al-5Zr-1.1B grain refiner and the ZrB2 particles could act as the heterogeneous nuclei of α-Mg grains. With the increase of the addition amount of Al-5Zr-1.1B grain refiner, the α-Mg grains of AZ91D magnesium alloy were refined from coarse dendrites to equiaxed grains. When the addition amount of Al-5Zr-1.1B grain refiner increased to 0.6%, the α-Mg grains of AZ91D magnesium alloy were refined to fine equiaxed grains with an average diameter of 45 μm, and the tensile strength and elongation of AZ91D magnesium alloy were improved to 195.3 MPa and 3.94%, respectively. The α-Mg grains average diameter of AZ91D magnesium alloy decreased by 73.5% and the tensile strength and elongation improved by 25.9% and 27.9% compared with that of AZ91D magnesium alloy without adding the Al-5Zr-1.1B grain refiner. It is concluded that the Al-5Zr-1.1B is an effective grain refiner to refine the α-Mg grains of AZ91D magnesium alloy.

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Li, X. R., Wei Liang, Xing Guo Zhao, and L. P. Bian. "Bonding of AZ91D Mg Alloy and Al Metal with Mg-Al Eutectic Alloy and its Application in Al Coating on AZ91D Mg Alloy." Materials Science Forum 610-613 (January 2009): 866–69. http://dx.doi.org/10.4028/www.scientific.net/msf.610-613.866.

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AZ91D magnesium alloy and Al metal were bonded successfully at 450 oC with load of 25 or 31 MPa by using Mg-Al eutectic alloy as the solder in atmosphere. The microstructure of the AZ91D/Al joints was characterized by SEM equipped with EDS, and the bond strength was measured through three-point bending test. It was revealed that reactive diffusion occurred obviously at the jointing part. The diffusion layers are composed of α-Mg + β-Mg17Al12, β-Mg17Al12, γ-Mg2Al3 and α-Al. The average bend strength of AZ91D/Al joints is 24 MPa with maximum value 28 MPa. To demonstrate the potential engineering application of this technology, AZ91D magnesium alloy plate was coated with Al foil and its corrosion resistance was tested. Electrochemical test results showed that the corrosion resistance of Al coated AZ91D magnesium alloy plate was greatly improved compared with the uncoated one.

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Li, Wei Hong, Ji Xue Zhou, Bai Chang Ma, Jian Hua Wu, Jin Wei Wang, Hai Hua Zhuang, Yuan Sheng Yang, and Xiao Hui Huang. "Protective Ability of Graphite Powder on Molten AZ91D Magnesium Alloy." Materials Science Forum 898 (June 2017): 111–17. http://dx.doi.org/10.4028/www.scientific.net/msf.898.111.

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Graphite powder was used to prevent a molten AZ91D magnesium alloy from oxidation and burning in order to develop a new pollution-free protection method with low cost. The protection method is expected to have good protective effect without decreasing the mechanical properties of the alloy. The protective ability of graphite powder on the alloy was investigated. Experimental results showed that graphite powder could protect AZ91D melt. The protective ability increased with graphite powder amount and decreased with holding time. The microstructure, chemical composition and phase composition of the surface films formed on the molten AZ91D alloy were analyzed using scanning electron microscopy, energy dispersive spectrometer and X-ray diffraction, respectively. The protection mechanism was discussed. The surface films produced by the reactions between graphite powder, AZ91D alloy melt and the ambient atmosphere had two layers. The continuous and compact outer layer, mainly consisting of MgO and C, may be the fundamental reason for the fact that graphite powder could protect AZ91D alloy melt.

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Huang, Wei Jiu, Rong Chang Zeng, and An Hua Chen. "A Comparative Study on the Fretting Wear Resistant Properties of AZ91D and AM60B Magnesium Alloys." Materials Science Forum 488-489 (July 2005): 745–48. http://dx.doi.org/10.4028/www.scientific.net/msf.488-489.745.

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The paper studied the fretting properties and the fretting mechanism of AZ91D and AM60B magnesium alloy. The results showed that the AZ91D alloy displayed lower friction coefficient and smaller wear volume than those of AM60B alloy, and also showed superior ability than those of AM60B in resisting crack nucleation and propagation. The fretting wear mechanisms of AZ91D and AM60B alloy were similar, including adhesion wear, surface fatigue wears and abrasive wear.

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Xu, Hong, Xin Zhang, Chang Shun Wang, Jin Chuan Hu, Cheng Wang, Chang Hua Liu, and Wei Hua Zhang. "Semi-Solid Moulding of AZ91D Magnesium Alloy." Materials Science Forum 850 (March 2016): 790–801. http://dx.doi.org/10.4028/www.scientific.net/msf.850.790.

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AZ91D magnesium alloy is one of the most widely used magnesium alloys in the production of metal forming, which use the characteristics from liquid state to solid state of metal to form. The present status of the research and application of the semi-solid forming for AZ91D magnesium alloys at present was reviewed in this paper, including the microstructural characteristics, the thixotropic and rheological behavior, the forming process of semi-solid for AZ91D magnesium alloys and the mechanical properties of the parts made of semi-solid magnesium alloys. The developing prospects and the key points of the semi-solid forming for AZ91D magnesium alloys were forecasted, and the industrial application of the alloy were also discussed.

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Li, Shu Hua, and Fu Chi Wang. "Corrosion Resistance of the Ceramic Coating Formed by Micro-Plasma Arc Oxidation on AZ91D Alloy." Key Engineering Materials 336-338 (April 2007): 2451–53. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.2451.

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The ceramic coating was formed by micro-plasma arc oxidation (MPAO) on AZ91D magnesium alloy. The surface and section morphology of coatings were observed using scanning electron microscopy. The phase composition of coatings was analyzed by X-ray diffraction. The method of salt fog experimental was carried out to proof-test performances of anti-corrosion of material. The results showed that the ceramic coating was composed by loose layer and compact layer. The coating surface has a large number of grains with various sizes. In addition, there is also a lot of pore in the loose layer, but the compact layer is tighter than the loose layer. Compact layer has a good combination with substrate magnesium alloy. The MPAO coating is mainly composed of silica oxide (MgAl2Si3O12 and β-Mg2SiO4 and (Mg4Al14) (Al4Si2)O20) and composite oxide of Mg and Al (δ-MgAl28O4). The performance of resistant corrosion of AZ91D coved by ceramic coating is higher than AZ91D magnesium alloy. The corrosion ratio of AZ91D alloy coved by ceramic coatings to AZ91D alloy is 1:8.61.

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Hao, Xi, Weixin Hao, Guihong Geng, Teng Ma, Chen Wang, Fuqiang Zhao, Hao Song, and Yugui Li. "Effects of High-Density Pulse Currents on the Solidification Structures of Cu-SiCp/AZ91D Composites." Advances in Materials Science and Engineering 2019 (April 3, 2019): 1–6. http://dx.doi.org/10.1155/2019/1684580.

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In this study, Cu-SiCp/AZ91D composites were prepared with high-density pulse currents. The wettability between SiCp and matrix during solidification was improved by coating 0.095-μm thick copper film on the surface of SiCp. By comparing the composites prepared with/without pulse currents, the solidification structure and its formation mechanism of Cu-SiCp/AZ91D composites were analyzed under different conditions. The Cu-SiCp/AZ91D composites prepared without high-density pulse currents were mainly composed of α-Mg, β-Mg17Al12, and a small amount of Mg2Si phases, with coarse grains and uneven structures. Under the action of high-density pulse currents, the structures of Cu-SiCp/AZ91D composites were transformed into α-Mg and Mg2Si phases with refined grain, and the homogeneity of the structures was improved significantly.

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Li, Ji Qiang, Zi Tian Fan, Xuan Pu Dong, Wen Liu, and Xianyi Li. "Microstructure and Mechanical Properties of Lost Foam Casting AZ91D Alloy Produced with Mechanical Vibration." Advanced Materials Research 213 (February 2011): 5–8. http://dx.doi.org/10.4028/www.scientific.net/amr.213.5.

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Mechanical vibration was introduced into the solidification in order to overcome the defects of coarse microstructure and low mechanical properties of the AZ91D magnesium alloy via lost foam casting（LFC）. The microstructure with fine uniform dendrite grains were achieved with mechanical vibration, which was mainly attributed to the cavitation and the melts flow induced by the mechanical vibration. The mechanical vibration has strong influence on the mechanical properties of AZ91D alloy. With application of mechanical vibration, the ultimate tensile strength and elongation of the AZ91D alloy increase 23% and 26%, resepectively.

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Xia, Ming Xu, Yan Huang, Zen Cassinath, and Zhong Yun Fan. "Rheo-Extrusion of AZ91D." Solid State Phenomena 192-193 (October 2012): 470–75. http://dx.doi.org/10.4028/www.scientific.net/ssp.192-193.470.

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The process of a novel rheo-extrusion was investigated by the combination of theoretical analysis and experimental verification based on a prototype counter rotating twin screw extruder. The investigation on the viscosity variation of AZ91D slurry and heat exchange of the system during extrusion shows both extrusion temperature and speed can affect the temperature and viscosity of the slurry. Thus, a continuous mass flow can be established by setting proper processing parameters to prevent bridging phenomenon in the extrusion according to the analysis. A thermal strategy for continuous output was setup at the highest extrusion speed of the extruder after investigation. The feasibility of the process and thermal strategy was then demonstrated by extruding an AZ91D rod using rheo-extrusion method.

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Huang, Wei Jiu, Miao Yao, Xiao Bin Zhang, and Lin Lin Huang. "Comparative Study on Tribological Behaviour between AZ71E and AZ91D Alloys under Ambient and Elevated Temperature." Advanced Materials Research 146-147 (October 2010): 873–78. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.873.

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The tribological properties of AZ71E and AZ91D magnesium alloys were comparatively investigated at ambient and elevated temperature. The results indicated that the wear rates of both alloys increased with increasing load, whereas the friction coefficients decreased with increasing load. The wear resistance of AZ71E alloy was significantly superior to that of AZ91D at higher loads and elevated temperature. At ambient temperature, abrasive wear is the predominant wear mechanism for AZ71E, whereas the wear mechanism for AZ91D transfers from abrasive wear to delaminative wear. At elevated temperature, the predominant wear mechanism of both alloys changed from mild wear regime to severe wear regime.

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Lin, Bi Lan, Yu Ye Xu, and Wei Su. "Effect of Immersion Time on Corrosion Resistance of Phytic Acid Coatings on AZ91D-Mg Alloy." Applied Mechanics and Materials 105-107 (September 2011): 1653–56. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.1653.

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Phytic acid coatings were formed on AZ91D-Mg alloy during immersion in 5.0 g/L phytic acid solution for different time. The corrosion resistance of the bare and coated samples was investigated using Tafel polarization and Electrochemical Impedance Spectroscopy (EIS) methods, and the corresponding electrochemical corrosion parameters were analyzed. The results show that the anodic and cathodic corrosion processes of AZ91D-Mg alloy are conspicuously inhibited with phytic acid coatings; the overall corrosion resistance index of AZ91D-Mg alloy is increased with immersion time; and the corrosion protection efficiency of phytic acid coatings is up to 97.8%.

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30

Sun, Qing Zhu, Hai Bo Wang, and Yong Chang Zhu. "Effect of Alloying Elements on the Microstructure and Properties of AZ91D-xCa-ySr." Advanced Materials Research 591-593 (November 2012): 993–96. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.993.

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In this paper, the microstructure and properties of AZ91D-xCa-ySr were studied by adding alloying elements. The mechanical properties were investigated by WDT-10 micro-electric universal testing machine and WD-T low cycle fatigue testing machine. The OLYMPUS-GX71 Optical electronic microscope, XRD and SEM were employed to investigate the microstructure of AZ91D. The results showed that the grains were refined by adding Ca,Sr,Gd and Y. Low cycle fatigue (LCF) behavior of AZ91D-0.4Ca-0.3Sr was improved obviously by adding 3.0%Gd and 3.0%Y into material, the tensile strengthen was up to 299Mpa, the elongation was 0.78%.

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31

Yang, Yuan Sheng, Quan Zhou, and Zhuang Qi Hu. "The Influence of Electric Current Pulses on the Microstructure of Magnesium Alloy AZ91D." Materials Science Forum 488-489 (July 2005): 201–4. http://dx.doi.org/10.4028/www.scientific.net/msf.488-489.201.

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The microstructure evolution of magnesium alloy AZ91D solidified with different electric current pulses and cooling rates was investigated and a new method, Low-voltage Electric Current Pulses (LVECP), to produce semi-slurry magnesium alloy was developed in this paper. The experimental results showed that the electric current pulses during solidification changed morphology of dendrites and the equiaxed, non-dendritic grains formed. The size of the primary a-Mg particles in semi-solid AZ91D alloy and the sphericity of the particles decreased with increase of discharging the voltage and treating time of LVECP. The increase of the cooling rate during the solidification of AZ91D alloy with LVECP promoted the formation of finer a-Mg particles, but the value of the sphericity of the particles rised. The formation of equiaxed, nondendritic structure by LVECP might be attributed to the electric current pulses increase the nucleation rate, restrained growth of the dendrites, and made dendrite arms remelted during the solidification of AZ91D alloy.

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32

Mu, Wei Yi, Rui Xue Luo, Zheng Xian Li, Ji Hong Du, and Zheng Ping Xi. "Effects of Applied Voltages on Micro-Arc Oxidized Coatings of Magnesium Alloy AZ91D in Aluminate Solution." Advanced Materials Research 154-155 (October 2010): 471–74. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.471.

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Micro-arc oxidation coatings were prepared on magnesium alloy AZ91D substrates at the different applied voltages in aluminate solution. The morphologies, phase components, and corrosion resistances of the coatings were investigated. The effect of the applied voltages on the microstructure and corrosion resistance of the coatings was also discussed. The results indicate that the coatings are uniform in thickness, and mainly composed of MgAl2O4 and MgO. There were many residual discharging channels on the coatings surface. The coatings improved the corrosion resistances of magnesium alloy AZ91D considerably. With the increase of the applied voltage, the thickness and the MgAl2O4 content of the coatings increase, while no significant variation is observed in the MgO content. The coatings surface becomes lower porosity and larger pore size with increasing of the applied voltage. In addition, the corrosion resistances of the coatings on magnesium alloy AZ91D surface are obviously superior to the magnesium alloy AZ91D substrate in the 3.5 wt. % NaCl solutions, and the effect is more remarkable at higher voltage.

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33

He, Zhao, Cheng, Shangguan, Wen, and Wang. "Influence of a Zn Interlayer on the Interfacial Microstructures and Mechanical Properties of Arc-Sprayed Al/AZ91D Bimetals Manufactured by the Solid–Liquid Compound Casting Process." Materials 12, no. 19 (October 8, 2019): 3273. http://dx.doi.org/10.3390/ma12193273.

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A novel technique combining solid–liquid compound casting (SLCC) with arc spraying was designed to manufacture the arc-sprayed Al/AZ91D bimetals with a Zn interlayer. The Al/Mg bimetal was produced by pouring the AZ91D melt into the molds sprayed with Al/Zn double-deck coating, during which the arc-sprayed Zn coating acted as the interlayer. The effect of the Zn interlayer on microstructures, properties, and fracture behaviors of arc-sprayed Al/AZ91D bimetals by SLCC was investigated and discussed in this study. The optimal process parameter was acquired by analyzing the results from different combinations between the arc-spraying time of the Zn coating (10, 18, and 30 s) and the preheat time of the Al/Zn double-deck coating (6 and 12 h). The interfacial microstructures of the arc-sprayed Al/AZ91D bimetals with a Zn interlayer could be approximately divided into two categories: One was mainly composed of (α-Mg + Al5Mg11Zn4) and (α-Al + Mg32(Al, Zn)49) structures, and the other primarily consisted of (α-Mg + Al5Mg11Zn4), (MgZn2 (main) + β-Zn), and (β-Zn (main) + MgZn2) structures. In the interface zone, the (α-Mg + Al5Mg11Zn4) structure was the most abundant structure, and the MgZn2 intermetallic compound had the highest microhardness of 327 HV. When the arc-spraying time of the Zn coating was 30 s and the preheat time of the Al/Zn double-deck coating was 6 h, the shear strength of the arc-sprayed Al/AZ91D bimetal reached 31.73 MPa. Most rupture of the arc-sprayed Al/AZ91D bimetals with a Zn interlayer occurred at the (α-Mg + Al5Mg11Zn4) structure and presented some typical features of brittle fracture.

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34

Liu, Guan Jun, Zhou Yu, Li Jie Ma, and Jun Cao. "Optimizing of Pretreatment Process of Electroless Ni-P Plating on AZ91D Substrate." Advanced Materials Research 239-242 (May 2011): 1915–18. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.1915.

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In order to improve and simplify the process of electroless Ni-P plating on AZ91D magnesium alloy substrate, pretreatment process and deposite time were optimized by orthogonal test, the plating morphology were analysed using Quanta 200 type scanning electron microscope. The bond between the plating and aluminum substrate were evaluated using method of water quenching and alternating bending test. The results show that good coating can be obtained on AZ91D substrate under the condition of the acid electroless Ni-P plating solution with pickling time of 40-50s, activated time of 10 min. And the good bond between the coating and AZ91D substrate was obtained.

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35

Yu, Si Rong, Zhi Qiu Huang, and Jia An Liu. "Thermodynamics of In Situ Formation of Mg₂Si and MgO in AZ91D /Flyash Composites." Materials Science Forum 686 (June 2011): 378–81. http://dx.doi.org/10.4028/www.scientific.net/msf.686.378.

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Novel AZ91D Mg alloy/fly-ash cenospheres (AZ91D/FAC) composites were fabricated by melt stir technique. The thermodynamic analyses of the interfacial reactions, the microstructure observation, and the phase analyses of the AZ91D/FAC composites were investigated. The results showed that the cenospheres were almost filled with Mg alloy matrix. In-situ MgO and Mg2Si phases were formed in Mg alloy matrix and near the interfaces between the cenospheres and Mg alloy matrix. Through the thermodynamic calculation, it can be found that the standard free enthalpy changes of these interfacial reactions are all negative at the temperature of Mg alloy melt preparation in this work, and these reactions can occur.

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36

Azadi, Mat Akhir Khalid, M. Z. M. Zamzuri, S. Norbahiyah, M. R. N. Liyana, M. Marina, K. Alir, and M. N. Derman. "Characteristic and Corrosion Studies of Rare Earth (Ree) Based Anodizing on AZ91D Magnesium Alloy." Advanced Materials Research 879 (January 2014): 38–42. http://dx.doi.org/10.4028/www.scientific.net/amr.879.38.

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Oxide coatings on AZ91D magnesium alloy were prepared using anodizing technique with 10mA/cm2 current density for 5 minutes in electrolyte containing La (NO3) and Mg (NO3),with NaVO3 as an additive. The corrosion behaviors of different coatings condition were evaluated by immersion test in 5.0% NaCl electrolyte for 72 hours. The microstructures were analyzed by Optical Microscope (OM) and Scanning Electron Microscope (SEM). It was found that coatings with the addition of NaVO3 produced homogeneous primary α-matrix and bigger β-phase (Mg17Al12) compared to untreated AZ91D magnesium alloy. The oxide film formed by anodizing in electrolyte with NaVO3 enhances the corrosion resistance of the AZ91D magnesium alloy significantly

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37

Azadi, Mat Akhir Khalid, M. Z. M. Zamzuri, S. Norbahiyah, and Mohd Nazree Derman. "Characteristic and Corrosion Studies of Rare Earth (REE) Based Anodizing on AZ91D Magnesium Alloy." Key Engineering Materials 594-595 (December 2013): 571–74. http://dx.doi.org/10.4028/www.scientific.net/kem.594-595.571.

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Oxide coatings on AZ91D magnesium alloy were prepared using anodizing technique with 10mA/cm2 current density for 5 minutes in electrolyte containing Mg (NO3)2 with NaVO3 as an additive. The corrosion behaviors of different coatings condition were evaluated by immersion test in 5.0% NaCl electrolyte for 72 hours. The microstructures were analyzed by Optical Microscope (OM) and Scanning Electron Microscope (SEM). It was found that coatings with the addition of NaVO3 produced homogeneous primary α-matrix and bigger β-phase (Mg17Al12) compared to untreated AZ91D magnesium alloy. The oxide film formed by anodizing in electrolyte with NaVO3 enhances the corrosion resistance of the AZ91D magnesium alloy significantly.

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38

Kaido, Masahiro, Kenta Imai, Masahiko Hatakeyama, and Satoshi Sunada. "Influence of β-Mg₁₇Al₁₂ Phase on Initial Pitting Process of AZ91D Magnesium Alloy." Materials Science Forum 879 (November 2016): 1895–98. http://dx.doi.org/10.4028/www.scientific.net/msf.879.1895.

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AZ91D magnesium alloy for casting is significantly corroded in chloride environment. In addition, Al-rich-α phase, which is formed during cooling process around β-Mg17Al12 phase, is one of the important factors on corrosion behavior in AZ91D. It is expected that pitting formation is dominant in the corrosion behavior in magnesium alloys. To clarify the influence of the Al-rich-α phase to pitting formation and corrosion behavior in AZ91D alloy, we have investigated the relationship between Microstructure and pitting formation in this study. We have carried out polarization curve measurement and scanning electron microscope (SEM) observation before and after the corrosion-tests. SEM micrograph of as-cast samples showed AZ91D alloy consist of α phase, Al-rich-α phase which shows bright Z-contrast due to high Al contents and β phase. Al-rich-α phase formed around β phase. After the corrosion examination, holes were observed at Al-rich-α phase around the β phase, and it is thought that small pits grow up to be holes, because β phase is remained, while the Al-rich-α phase around the β phase preferentially dissolves with time. The result indicates that Al-rich-α phase around β phase enhance the formation of pitting and preferentially dissolve it in initial stage of corrosion in AZ91D alloy.

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39

Hsiao, Houng-Yu, and Wen-Ta Tsai. "Effect of heat treatment on anodization and electrochemical behavior of AZ91D magnesium alloy." Journal of Materials Research 20, no. 10 (October 2005): 2763–71. http://dx.doi.org/10.1557/jmr.2005.0349.

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The anodic films formed on AZ91D magnesium alloy after heat treatment were analyzed and their electrochemical properties were investigated. The results showed that the cooling rate had a significant influence on the microstructure evolution of the AZ91D magnesium alloy after solution heat treatment at 440 °C for 20 h in N2 atmosphere. A single-phase microstructure was observed when the alloy was quenched in water after solution heat treatment. However, a duplex structure consisting of both α and β phases was found if the solution-annealed alloy was cooled in air. The differences in microstructure of the heat treated AZ91D magnesium alloy gave rise to a significant change in the property of the anodic film formed in 3 M KOH + 0.21 M Na3PO4 + 0.6 M KF + 0.15 M Al(NO3)3 electrolyte. During the early stage of anodization, for the as-cast alloy, inhomogeneous anodic films were formed exhibiting relative rough surface appearances. A rather smooth anodic film was formed for the solution-annealed AZ91D magnesium alloy either followed by air cooling or water-quenched. The surface and cross section appearance was almost the same regardless of the prior heat treatment after anodizing for 20 min. The corrosion resistances of the various anodized AZ91D magnesium alloy were evaluated and compared by employing electrochemical impedance spectroscopy (EIS). The results demonstrate that the anodic film formed on the water-quenched AZ91D magnesium alloy had a slightly higher polarization resistance than that formed on the as-cast alloy. The highest polarization resistance of anodic film was found for that formed on annealed and air-cooled alloy. The presence of Al-rich β phase on the surface gave rise to the formation of a more protective anodic film which consisted of a great amount of Al2O3.

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40

Suo, Xin Kun, Xue Ping Guo, Wen Ya LI, Marie Pierre Planche, Chao Zhang, and Han Lin Liao. "Microstructure and Wear Behavior of SiC_P-Reinforced Magnesium Matrix Composite by Cold Spraying." Advanced Materials Research 314-316 (August 2011): 253–58. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.253.

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In this paper, dense AZ91D/SiC composite coatings were fabricated by cold spraying. The microstructure and microhardness of the as-sprayed coatings were investigated. The results show that the content of SiC particles in the composite coating was 23.6 ± 7.5 vol.%. The microhardness of the composite coating was improved to 140 HV0.3 due to the enhancement of SiC particles, compared to 98 HV0.3 for the pure AZ91D coating. The wear behavior of the composite coating in an ambient condition was studied through a ball-on-disc dry sliding test system. The composite coating showed higher friction coefficient and lower wear rate than the pure AZ91D coating. The wear mechanism of the composite coating was discussed.

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41

Huang, Kai Jin, Yu Yue Wang, and Xin Lin. "Microstructure and Wear Resistance of Cu_0.9NiAlCoCrFe High Entropy Alloy Coating on AZ91D Magnesium Alloys by Laser Cladding." Advanced Materials Research 989-994 (July 2014): 246–50. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.246.

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To improve the wear properties of AZ91D magnesium alloys, a Cu0.9NiAlCoCrFe high entropy alloy (HEA) coating was fabricated on AZ91D magnesium alloys by laser cladding using prealloyed Cu0.9NiAlCoCrFe powders. The microstructure of the HEA coating was characterized by OM, SEM and XRD. The wear resistance of the HEA coating was evaluated under dry sliding wear test condition at room temperature. The results show that the HEA coating mainly consists of a simple BCC solid solution phase. The HEA coating exhibits excellent wear resistance. The main wear mechanisms of the HEA coating and the AZ91D substrate were different, the former dominated by oxidative abrasive wear and the latter suffered from both adhesive and abrasive wear.

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42

Jia, Su Qiu, Jing Xin Guan, Zhan Kui Zhao, Hua Chen, and Shu Yan Jia. "Optimization of Process Parameters for Electroless Ni-P Plating on AZ91D Magnesium Alloy by Phosphate Pretreatment." Advanced Materials Research 418-420 (December 2011): 808–11. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.808.

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Electroless nickel plating coatings on AZ91D alloy by phosphate pretreatment were prepared. The coating resembles a cauliﬂower and is compact. It consists of amorphous Ni-P. Potentiodynamic polarization curves of the Ni-P coatings in 3.5% NaCl show that the electroless Ni-P coating improves the corrosion resistance of AZ91D alloy and the highest corrosion potential reached to -0.513V vs. SCE. The results of the orthogonal experiment of process parameters indicates that temperature 80°C, time 120min and pH 7.5 can be considered as the optimum process parameters for electroless Ni–P plating on AZ91D alloy and pH value in the bath has more effect on corrosion potential than temperature and time.

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43

Zhang, Y. K., Xiao Shi Hu, Kun Wu, and Ming Yi Zheng. "Application of G-L Dislocation Model in Low Frequency Damping Capacities of AZ91D and SiCw/AZ91D Composites." Materials Science Forum 546-549 (May 2007): 495–98. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.495.

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The low frequency damping capacities of commercial cast AZ91D, squeeze cast AZ91D alloy and SiCw/AZ91D composite were studied using dynamic mechanical analyzer (DMA). The obtained strain amplitude dependent damping could be divided into two regions. In the region of small strain amplitude, the damping capacity was independent of the amplitude. While at high strain region, the damping capacity increased rapidly with increasing of strain amplitude. The G-L dislocation model was used to explain the damping capacity, and the differences of the distance between the weak and strong pinning points were discussed. The microstructures of the alloys and composites were observed and coincided with the analysis results according to G-L dislocation model.

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44

Xia, Cun Juan, Ming Liang Wang, Hao Wei Wang, and Cong Zhou. "The Effect of Aluminum Content on TiO₂ Coated Carbon Fiber Reinforced Magnesium Alloy Composites." Applied Mechanics and Materials 488-489 (January 2014): 30–35. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.30.

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The interface between the reinforcement and the matrix is significant to metal matrix composites. The effect of aluminum (Al) content on interfacial microstructure and mechanical properties of TiO2coated carbon fiber reinforced magnesium matrix composites by squeeze casting technique have been studied (C/Mg). Mg-2wt%Al and AZ91D were used as alloy matrix. The obtained results indicate that the carbon fibers in both kinds of composites are well protected by TiO2coating, without any interfacial brittle carbide phase observed. The flexural strength of Cf-TiO2/AZ91D (1009MPa) composites is 26.5% lower than that of Cf-TiO2/Mg-2Al (1277MPa) composites. The lath-shaped precipitates of Mg17Al12in AZ91D composites lead to the mechanical properties decrease.

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45

Wang, Dong, Shou Ren Wang, Zhi Dong Zhang, and Wei Wu. "Manufacturing Technology Research of Magnesium Alloy Transmission Case." Advanced Materials Research 1095 (March 2015): 164–67. http://dx.doi.org/10.4028/www.scientific.net/amr.1095.164.

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Based on the AZ91D magnesium alloy transmission case model, the paper analyzes the strength of transmission case by FEM method and manufacture products through the lost foam casting process. Then analyzes microstructure, ultimate strength, yield strength, elongation and impact toughness by sampling method. The results that AZ91D magnesium alloy is a preferable material in the small transmission field.

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46

Zhang, Bao Hong, and Zhi Min Zhang. "Effect of Extrusion Ratio on Microstructure and Mechanical Properties of As-Cast AZ91D Magnesium Alloy." Advanced Materials Research 445 (January 2012): 237–40. http://dx.doi.org/10.4028/www.scientific.net/amr.445.237.

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In order to study the effect of deformation extent on microstructure and mechanical properties of as-cast AZ91D magnesium alloy, experiments of direct extrusion were performed at temperature of 420 and different extrusion ratios. The microstructure and mechanical properties of billets and extrudates were measured. Experimental results show that the grain size of as-cast AZ91D magnesium alloy can be dramatically refined by extrusion. Direct extrusion can obviously improve the mechanical properties of as-cast AZ91D magnesium Alloy, comparing with the pre-extruded billet, the tensile strength, yield strength and elongation of extrudate can be improved by at least 83%, 154% and 150% respectively. As the extrusion ratio increases, the tensile strength and yield strength of extrudate will increase at first and then fall.

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47

Wu, Ming, Fang Long, Hao Ran Geng, and Fang Yang. "Effects of Heat Treatment on Microstructure and Properties of AZ91D Magnesium Alloy." Key Engineering Materials 575-576 (September 2013): 410–13. http://dx.doi.org/10.4028/www.scientific.net/kem.575-576.410.

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The microstructure, hardness and corrosion resistance of AZ91D alloy were investigated under different solution treatments and artificial aging conditions.When ascast AZ91D alloy was heat treated at 415°C by solution treatmentfor 12 h and artificially aged at 200°C, the volume fraction of precipitates increased with the aging time up to 10 h.When ascast AZ91D alloy was treated at 430°C by solution treatment for 12 h and artificially aged at 200°C for 10h, the volume fraction of precipitates reached a peak value.The results of the corrosion test showed that a high corrosion resisting of the second phase precipitates was beneficial to improving the strength and hardness. Solution treatment at 445°C temperature for 12 h destroied the consecutiveness of β-Mg17Al12 phases.

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48

Huang, Kai Jin, Yu Yue Wang, and Xin Lin. "Microstructure and Wear Resistance of AlFeCuCoNiCrTi_1.5 High Entropy Alloy Coating on AZ91D Magnesium Alloys by Laser Cladding." Applied Mechanics and Materials 644-650 (September 2014): 4766–71. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.4766.

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To improve the wear properties of AZ91D magnesium alloys, a AlFeCuCoNiCrTi1.5high entropy alloy (HEA) coating was fabricated on AZ91D magnesium alloys by laser cladding using mixed powders of Al, Fe, Cu, Co, Ni, Cr, and Ti. The microstructure of the HEA coating was characterized by OM, SEM, and XRD. The wear resistance of the HEA coating was evaluated under dry sliding wear test condition at room temperature. The results show that the HEA coating mainly consists of a simple BCC solid solution phase. The HEA coating exhibits excellent wear resistance. The main wear mechanisms of the HEA coating and the AZ91D substrate were different, the former dominated by oxidative abrasive wear and the latter suffered from both adhesive and abrasive wear.

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49

Ferguson, W. G., Wu Liu, and John MacCulloch. "Corrosion - Fatigue Performance of Magnesium Alloys." International Journal of Modern Physics B 17, no. 08n09 (April 10, 2003): 1601–7. http://dx.doi.org/10.1142/s0217979203019381.

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To determine the effect of a coating on fatigue strength, three point bend fatigue tests of coated and un-coated AM50 and AZ91D magnesium high pressure die cast specimens were made and S-N curves determined. Environments used were air, tap water and natural seawater. A difference in corrosion fatigue performance has been found, between AZ91D and AM50 and for both alloys performance in air was superior to both water environments. AZ91D has better corrosion fatigue resistance in tap water than in seawater; conversely, AM50 has better corrosion fatigue resistance in seawater than tap water. The results showed that the fatigue life was not reduced in these water environments for coated specimens, as the coating usually provided protection from corrosion.

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50

Yang, You, Hua Wu, and Xue Song Li. "High Cycle Fatigue Behavior of Gravity Cast AZ91D Magnesium Alloy." Materials Science Forum 686 (June 2011): 157–61. http://dx.doi.org/10.4028/www.scientific.net/msf.686.157.

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High cycle fatigue behavior of gravity cast magnesium alloy AZ91D were investigated using an up-and-down load method. High cycle fatigue tests were carried out up to 107cycles at a stress ratio R=0.1 and frequency of 90Hz on specimens using a high frequency fatigue machine. Fatigue fracture surfaces of specimens that in the high cycle fatigue tests were also observed using a scanning electron microscope for revealing the micro-mechanisms of fatigue crack initiation and propagation. The results showed that fatigue limit of AZ91D alloy at room temperature is 54.5 MPa under the numbers of cycle to failure Nf=107 conditions using up-and-down method calculation. The fatigue strength of the alloy is about 32% of its tensile strength. The micro-fatigue fracture surface of AZ91D alloy included three representative regions. These regions are fatigue initiation area, fatigue crack propagation area and fatigue fracture area. Fatigue cracks of AZ91D alloy initiate principally at inclusions of alloy surface and subsurface, and propagate along the grain boundary. The fatigue striations of fatigue crack propagation area are not clear. The fatigue fracture of test specimens shows the rupture characteristics of quasi-cleavage.

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Journal articles on the topic 'AZ91D'

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