Journal articles: 'Mechanical erosion'

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Du, Jun, Ping Zhang, Xiao Ying Zhu, and Zhi Hai Cai. "The Microstructure and Mechanical Properties of ZrAlN/Cu Coating." Advanced Materials Research 284-286 (July 2011): 884–88. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.884.

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ZrAlN/Cu coating has been deposited onto Ti-6Al-4V substrates by reactive magnetron sputtering. The morphology of films was investigated by FESEM, the microstructure was studied by XRD, XPS and TEM. The plastic deformation characteristic of thin films were analysised from loading/unloading curves measured by nano-indentation method. Erosion tests were conducted to evaluate anti-erosion ability. Erosion rates were measured and characteristic damage features were identified on the surface of eroded specimens. The mechanisms of erosion are discussed in order to explain the promising performance of materials in erosive conditions. It was found that there is an significant increase of erosion resistance because of the increase of hardness and toughness.

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Levy, C., M. Perl, and Q. Ma. "The Influence of Finite Three-Dimensional Multiple Axial Erosions on the Fatigue Life of Partially Autofrettaged Pressurized Cylinders." Journal of Pressure Vessel Technology 125, no. 4 (November 1, 2003): 379–84. http://dx.doi.org/10.1115/1.1616582.

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Erosion geometry effects on the mode I stress intensity factor (SIF) for a crack emanating from the farthest erosion’s deepest point in a multiply, finite-length or full-length eroded, partially autofrettaged, pressurized, thick-walled cylinder is investigated. The problem is solved via the FEM method. Autofrettage, based on von Mises’ yield criterion, is simulated by thermal loading and SIFs are determined by the nodal displacement method. SIFs were evaluated for a variety of relative crack depths, a/t=0.01-0.30 and crack ellipticities, a/c=0.5-1.5 emanating from the tip of the erosion of various geometries, namely, (a) semi-circular erosions of relative depths of 1–10% of the cylinder’s wall thickness, t; (b) arc erosions for several dimensionless radii of curvature, r′/t=0.05-0.3; and (c) semi-elliptical erosions with ellipticities of d/h=0.5-1.5. In the cases of finite erosions, the semi-erosion length to the semi-crack length, Le/c, was between two and ten, erosion angular spacing, α, was between 7 and 120 degrees, whereas percent autofrettage investigated included 30%, 60%, and 100%. The normalized SIFs and the normalized effective SIFs of a crack emanating from the farthest finite erosion are found to rise sharply for values of Le/c<3. Both the normalized SIF and normalized effective SIF values are mitigated as the amount of partial autofrettage increases with the most rapid decrease occurring between 0–60% autofrettage. The purpose of this study is to detail these findings.

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MUIR WOOD, D., K. MAEDA, and E. NUKUDANI. "Modelling mechanical consequences of erosion." Géotechnique 60, no. 6 (June 2010): 447–57. http://dx.doi.org/10.1680/geot.2010.60.6.447.

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Siewert, Jens, and Carmelo Ferlito. "Mechanical erosion by flowing lava." Contemporary Physics 49, no. 1 (January 2008): 43–54. http://dx.doi.org/10.1080/00107510802077388.

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Perl, M., C. Levy, and H. Fang. "Cracks Emanating From an Erosion in a Pressurized Autofrettaged Thick-Walled Cylinder—Part II: Erosion Depth and Ellipticity Effects." Journal of Pressure Vessel Technology 120, no. 4 (November 1, 1998): 354–58. http://dx.doi.org/10.1115/1.2842343.

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In Part I of this paper, the effects of constant depth erosion on the mode I stress intensity factor (SIF) were determined for a crack emanating from the erosion deepest point in a pressurized, autofrettaged, thick-walled cylinder. The erosion geometries investigated included semi-circular erosions and several arc erosions of various radii of curvature. Due to the trends found in that portion of the study, erosion depth and ellipticity are believed to have equally important impact on the SIFs. The present paper delves further into these two parameters using the following configurations: (a) semi-circular erosions of relative depths of 1–10 percent of the cylinder’s wall thickness, W; and (b) semi-elliptical erosions with ellipticities of d/h = 0.3 – 2.0. Deep cracks are found to be practically unaffected by the erosion, similar to the results presented in Part I of the paper. The effective SIF for relatively short cracks is found to be dramatically enhanced by the stress concentration factor (SCF), which encompasses the depth of the erosion as well as its radius of curvature at the tip. As a result of the increased effective SIF, a significant decrease in the vessel’s fatigue life of up to an order of magnitude may occur.

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Levy, C., M. Perl, and Q. Ma. "Erosions and Their Effect on the Fatigue Life of Thick Walled, Autofrettaged, Pressurized Vessels." Journal of Pressure Vessel Technology 125, no. 3 (August 1, 2003): 242–47. http://dx.doi.org/10.1115/1.1593698.

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This paper summarizes the results that have been found in evaluating the effect of erosions on thick walled, autofrettaged, pressurized, cracked vessels. The problem is solved numerically via the FEM method. Autofrettage, based on von Mises yield criterion, is simulated by thermal loading and stress intensity factors (SIF’s) are determined by the nodal displacement method. SIF’s were evaluated for a variety of relative crack depths a/t and crack ellipticities a/c emanating from the tip of the erosion of various geometries, namely, (a) semi-circular erosions of small relative depths of the cylinder’s wall thickness t; (b) arc erosions for several dimensionless radii of curvature r′/t; and (c) semi-elliptical erosions with ellipticities of d/h. Other parameters evaluated were, in the cases of finite erosions, the semi-erosion length to the semicrack length Le/c, the erosion angular spacing α, and the autofrettage level. First, we summarize the differences found between a vessel with one erosion and one with multiple erosions. We show that for full cylinder length erosions, the erosions tend to make smaller cracks more dangerous than larger cracks in fully autofrettaged vessels and that as the crack grows the stress intensity factor initially decreases. We then show that as the crack grows further, the effect is to increase the effective stress intensity factor (SIF) but also to practically void the existence of the erosion. We show further that lower levels of autofrettage will lead to higher effective SIF’s but that partially eroded cylinders (cylinders where erosions are a fraction of the cylinder length) lead to lower SIF’s. Affecting these values in all cases, of course, are the erosion geometry and depth as well as the crack geometry and depth.

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Sharma, Rohit, Ashish Mehrotra, Vinit K. Sharma, Zafar Iqbal, and Kunal Nigam. "A Retrospective Study of Bony Erosion Patterns in Cases of Fungal Rhinosinusitis." An International Journal Clinical Rhinology 9, no. 2 (2016): 62–64. http://dx.doi.org/10.5005/jp-journals-10013-1269.

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ABSTRACT Erosion of bone with or without extension of disease into adjacent anatomic spaces is observed among some patients with fungal rhinosinusitis (FRS). Preoperative computed tomographies is very important to determine the sites of bony erosion. Patients with bony erosions are classified based on the involved subsite and the extent of erosion. Bony erosions was seen in 37.5% cases. Six patients were having bone erosions on CT scan. 40 % erosions were present in patients belonging to younger age group. Erosion of sinus boundaries were more common in male patients (60%). The ethmoid sinus complex was most commonly involved (46.6%). This was followed in frequency of involvement by the maxillary sinus (26.6%), the sphenoid sinus (20%) and the frontal sinus (6.6%). The most common site of erosion was the lamina papyracea (33.3%), followed by the medial maxillary wall (20%). Bony erosions due to FRS were mainly due to long-term mechanical compression by the fungal mass. A case of chronic rhinosinusitis with bony erosions in CT scan may indicate a fungal etiology. How to cite this article Sharma VK, Sharma R, Mehrotra A, Iqbal Z, Nigam K. A Retrospective Study of Bony Erosion Patterns in Cases of Fungal Rhinosinusitis. Clin Rhinol An Int J 2016;9(2):62-64.

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KRUPICZ, Bazyli, Mariusz LISZEWSKI, and Wojciech TARASIUK. "MECHANICAL PROPERTIES OF MATERIALS AND THEIR EROSIVE WEAR." Tribologia 269, no. 5 (October 31, 2016): 85–94. http://dx.doi.org/10.5604/01.3001.0010.6602.

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In this paper, the authors analyse the impact of selected mechanical properties of materials on their erosive wear caused by a steady stream of solid particles. A wear process is a function of the material properties of two materials that interact with each other in a given environment, i.e. the construction material and the particles that cause erosion. Erosive losses occur upon reaching a critical condition of damaging an element of the material’s surface under the influence of kinetic energy that result from incident particles of an abrasive material. It is proposed that the critical condition that accompanies the formation of erosion losses should be represented by the toughness (U) and the specific work of the deformation of the sample in the tensile strength test (W). The study involved the following materials: NC6, 42CrMo4, 20MnCr5, and S235JR.

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Duan, Long Chen, Anne Neville, and Yu Yan. "Experimental Research on Erosion and Corrosion of WC-Base Matrix Materials for Drill Bits under Impingement of Drilling Muds." Key Engineering Materials 359-360 (November 2007): 171–75. http://dx.doi.org/10.4028/www.scientific.net/kem.359-360.171.

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In oil drilling the failures of PDC drill bits are exhibited as erosive wear, dropping and breaking of cutters, so the erosion and corrosion resistance of the matrix is one of the key factors affecting the quality of PDC bits. In order to understand the degradation mechanism of matrix materials for drill bits, a kind of loop recirculation rig is adopted to measure total mass loss TML, mass loss E by pure mechanical erosion, and then through calculation the mass loss C+S by corrosion and synergy is obtained. The tested and calculated results show that TML of matrix materials is not only caused by pure mechanical erosion, but also by corrosion and their synergy of mechanical erosion and corrosion. In the discussed scope of this paper the volume loss produced by corrosion and synergy is 24.16% of the total volume loss (TVL) at most, which tells us that the corrosion resistance of matrix materials should be considered carefully besides their erosive resistance in the design and selection of PDC drill bits used in the corrosive drilling muds.

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Ke, Lin, and Akihiro Takahashi. "Triaxial Erosion Test for Evaluation of Mechanical Consequences of Internal Erosion." Geotechnical Testing Journal 37, no. 2 (January 20, 2014): 20130049. http://dx.doi.org/10.1520/gtj20130049.

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Barik, R. C., J. A. Wharton, R. J. K. Wood, and K. R. Stokes. "Electro-mechanical interactions during erosion–corrosion." Wear 267, no. 11 (October 2009): 1900–1908. http://dx.doi.org/10.1016/j.wear.2009.03.011.

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Chang, Dongsheng, Limin Zhang, and Johnny Cheuk. "Mechanical consequences of internal soil erosion." HKIE Transactions 21, no. 4 (October 2, 2014): 198–208. http://dx.doi.org/10.1080/1023697x.2014.970746.

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Harrison, C. G. A. "What factors control mechanical erosion rates?" International Journal of Earth Sciences 88, no. 4 (March 22, 2000): 752–63. http://dx.doi.org/10.1007/s005310050303.

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Dallimore, Scott R., Stephen A. Wolfe, and Steven M. Solomon. "Influence of ground ice and permafrost on coastal evolution, Richards Island, Beaufort Sea coast, N.W.T." Canadian Journal of Earth Sciences 33, no. 5 (May 1, 1996): 664–75. http://dx.doi.org/10.1139/e96-050.

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A long-term sediment budget (1947−1985) for northern Richards Island shows that, when ground ice and offshore erosion are accounted for, there is a near balance between headland erosion and coastal deposition. Excess ice constitutes about 20% of the total volume of eroded material from the headlands, with massive ground ice contributing nearly 9% and segregated ice lenses and ice wedges making up the remainder. Coastal response to major storms in 1987 and 1993 suggests that erosion is episodic, with short periods of intense disruption followed by readjustment of cliff profiles. Processes characteristic of this environment include mechanical erosion of ice-bonded sediments creating unstable erosional niches, mechanical failure of niches along ice-wedge planes, and longer term thermal erosion of ice-bonded sediments. Where ice contents are high, localized thaw slumps initiated by coastal erosion may retreat at rates substantially higher than those observed at other sections of the coast. Cliff-top retreat rates may be out of phase with storm-event chronology.

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Du, Jun, Ping Zhang, Jun Jun Zhao, and Zhi Hai Cai. "Erosion-Resistant PVD ZrAlCuN Coating for Titanium Alloy." Advanced Materials Research 150-151 (October 2010): 51–55. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.51.

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Titanium alloys are susceptible to sand erosion, hard zirconium nitride coatings have been deposited onto titanium alloys by Physical vapor deposition (PVD) in order to improve erosion resistance. Al and Cu were added into ZrN coatings to strength and toughing the coating. The microstructure and mechanical properties of ZrAlCuN coating were studied. Erosion tests were conducted to evaluate anti-erosion ability. Erosion rates were measured and characteristic damage features were identified on the surface of eroded specimens. The mechanisms of erosion are discussed in order to explain the promising performance of materials in erosive conditions. It was found that there is an significant increase of erosion resistance because of the increase of hardness and toughness.

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Dobiáš, J. "Forest road erosion." Journal of Forest Science 51, No. 1 (January 10, 2012): 37–46. http://dx.doi.org/10.17221/4542-jfs.

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The forest road network influences surface runoff of uninfiltrated precipitation water on forest lands, mainly in hilly and mountainous areas. This water flows onto the road crown in unpaved forest roads that do not have any ditches. Dragging of extracted logs causes mechanical damage to the crown of unpaved forest road, and tracks after tractor wheels and furrows after dragged logs originate. Flowing water is accumulated in these depressions and the water stream causes erosion. The method for evaluation of conditions for the origination and degree of this erosion damage consists in the calculation of tangential stresses near the bottom at various depths of water and various gradients of road. Limit gradients of road for the origination of greater or smaller damage by erosion for the subsoil grain of various sizes are determined by a comparison of calculated tangential stresses with critical tangential stresses. Rates of discharge were calculated for the particular models of damage.

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Perl, M., C. Levy, and J. Bu. "Three-Dimensional Analysis of a Semi-Elliptical Crack Emanating From an Erosion at the Bore of an Autofrettaged Pressurized Cylinder." Journal of Pressure Vessel Technology 121, no. 2 (May 1, 1999): 209–15. http://dx.doi.org/10.1115/1.2883688.

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The effect of various erosion configurations on the mode I stress intensity factor (SIF) distribution along the front of a semi-elliptical crack, emanating from the deepest line of the erosion surface (DLES) at the bore of an autofrettaged, pressurized thick-walled cylinder of outer to inner radius ratio, Ro/Ri = 2, is investigated. The three-dimensional (3-D) linear elastic problem is solved via the finite element (FE) method using the ANSYS 5.2 standard code. Hill’s autofrettage residual stress field is simulated by an equivalent thermal load and the SIFs are determined by the nodal displacement method. SIF distribution along the front of semi-elliptical cracks of various crack depths to wall thickness ratios, a/t = 0.05 to 0.25, and ellipticities, a/c, ranging from 0.5 to 1.5, emanating from the DLES, are determined. Three groups of erosion geometries are considered: (a) arc erosions of constant relative depth, d/t, equal to 5 percent and with relative radii of curvature, r′/t, between 5 and 30 percent; (b) semi-elliptic erosions of constant relative depth, d/t, of 5 percent with erosion ellipticity, d/h, varying from 0.3 to 2.0; and (c) semi-circular erosions of relative depth, d/t, between 1 and 10 percent of the wall thickness. The effective SIF along the crack front results from the superposition of KIP—the SIF due to pressurization, and KIA—the negative SIF due to the autofrettage residual stress field. KIP is highly dependent on the stress concentration ahead of the DLES which directly relates to the erosion geometry. The absolute value of KIA is just slightly reduced by the presence of the erosion. Its change solely depends on, and is directly proportional to, the erosion depth. Thus, while deep cracks are almost unaffected by the erosion, the effective SIF for relatively short cracks is found to be significantly enhanced by its presence and might result in a shortening of the vessel’s fatigue life by up to an order of magnitude. Also, it is shown that 2-D analysis may lead to a nonconservative estimate of the vessel’s fatigue life.

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Menguturk, M., D. Gunes, M. Erten, and E. F. Sverdrup. "Multistage Turbine Erosion." Journal of Turbomachinery 108, no. 2 (October 1, 1986): 290–97. http://dx.doi.org/10.1115/1.3262050.

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This paper presents a computer package developed to calculate the blade erosion rates in multistage turbines that use particle-laden hot expansion gases. This package is an extension of the single-stage erosion code presented in some of our earlier papers. The present package calculates gas flow and particle trajectories in each stage. The calculated particle outlet conditions of a given stage are processed statistically to generate the particle inlet conditions to the next stage enabling trajectory and erosion calculations to be advanced beyond a single turbine stage. The package allows erosion predictions to be obtained either based on the semi-empirical erosion formula presented earlier or by using an improved model which relies upon direct interpolation of available experimental data. This computer package has been applied to a four-stage electric utility gas turbine. It has been found that, in addition to the first-stage rotor blades, as indicated by our earlier studies, the second-stage rotor and the second and third-stage stator blades may also be exposed to critical erosion damage.

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Zhu, Lei, and Hua Jie Zhang. "Research on the Shear Strength and Microstructure Change Regulation of Cement-Mixed Soil under Erosion Environment." Applied Mechanics and Materials 52-54 (March 2011): 1846–54. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.1846.

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In order to research the mechanical properties and microstructure change regulation of cement-mixed soil under erosion environment, several experiments are carried out in laboratory. The changes of shear strength of cement-mixed soil are recorded under different erosion environments and in different erosion periods. Their corresponding photomicrographs are also shot to reveal the damage on cement-mixed soil under erosion environment. The results indicate that the shear strength of cement-mixed soil in erosion solutions is worse than the strength by the natural curing in the corresponding period. As erosion time increases the strength of cement-mixed soil dipped in , and solutions keeps on downtrend, whereas the strength of that dipped in unpolluted water and solution presents upward trend. The erosive effects of cement-mixed soil are mainly caused by and , meantime has more prominent erosive effect on cement-mixed soil than . Accompanying with stadium increasing quantitative parameters of microstructures are all varying markedly and have certain regulation which testifies the notable relativity between the shear strength and microstructural parameters. Liner regression methods are set up to indicate the relationship of shear strength indexes and microstructural parameters in the erosion environment.

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Tronvoll, J., A. Skj˦rstein, and E. Papamichos. "Sand production: Mechanical failure or hydrodynamic erosion?" International Journal of Rock Mechanics and Mining Sciences 34, no. 3-4 (April 1997): 291.e1–291.e17. http://dx.doi.org/10.1016/s1365-1609(97)00195-0.

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Gravanis, E., E. Sarris, and P. Papanastasiou. "Hydro-mechanical erosion models for sand production." International Journal for Numerical and Analytical Methods in Geomechanics 39, no. 18 (May 4, 2015): 2017–36. http://dx.doi.org/10.1002/nag.2383.

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Ninham, Andrew. "The effect of mechanical properties on erosion." Wear 121, no. 3 (February 1988): 307–24. http://dx.doi.org/10.1016/0043-1648(88)90208-6.

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Chahine, G. L., and P. Courbie`re. "Noise and Erosion of Self-Resonating Cavitating Jets." Journal of Fluids Engineering 109, no. 4 (December 1, 1987): 429–35. http://dx.doi.org/10.1115/1.3242684.

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Self-resonating jets have been developed which take advantage of the natural tendency of a jet to organize in large structures. Tests have shown that these jets are both highly erosive and a source of a discrete frequency high level noise. Simultaneous investigations of the noise and erosion of these jets have been conducted and have shown a definite trend toward correlation. For instance, time evolution of volume removal rates of an impacted surface and rms readings of a pressure transducer have been found to be correlated. Similarly, shifts in the relative importance of the various frequencies have followed the advancement of erosion. These results could be of great advantage in the determination of the evolution of a jet cutting operation in progress. In this paper jet noise and erosion correlation tests will be described and the results analyzed.

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Filali, E. G., and J. M. Michel. "The Cavermod Device: Hydrodynamic Aspects and Erosion Tests." Journal of Fluids Engineering 121, no. 2 (June 1, 1999): 305–11. http://dx.doi.org/10.1115/1.2822208.

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The Cavermod (CAVitation ERosion MODel) is an erosion test device first described by Dominguez-Cortazar et al. (1992, 1997). Recently, it was modified in two steps: first by increasing its maximum rotation rate (from 4500 to 8000 rpm) and second by shortening its vapor core (from 156 to 66 mm). This paper plans to present the main results which are obtained in both configurations (long and short vortex) and for “slow” or “rapid” regime of rotation. They mainly concern 1. the hydrodynamic aspects of the vapor core collapse, as deduced from observation of rapid films (evolution of the vortex length, collapse, velocity), 2. the erosion patterns produced on metallic targets such as pure aluminium and copper. A second companion paper will present the results of force measurements in both configuration and an attempt to estimate the local erosive pressures.

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Pereira, F., F. Avellan, and Ph Dupont. "Prediction of Cavitation Erosion: An Energy Approach." Journal of Fluids Engineering 120, no. 4 (December 1, 1998): 719–27. http://dx.doi.org/10.1115/1.2820729.

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The objective is to define a prediction and transposition model for cavitation erosion. Experiments were conducted to determine the energy spectrum associated with a leading edge cavitation. Two fundamental parameters have been measured on a symmetrical hydrofoil for a wide range of flow conditions: the volume of every transient vapor cavity and its respective rate of production. The generation process of transient vapor cavities is ruled by a Strouhal-like law related to the cavity size. The analysis of the vapor volume data demonstrated that vapor vortices can be assimilated to spherical cavities. Results are valid for both the steady and unsteady cavitation behaviors, this latter being peculiar besides due to the existence of distinct volumes produced at specific shedding rates. The fluid energy spectrum is formulated and related to the flow parameters. Comparison with the material deformation energy spectrum shows a remarkable proportionality relationship defined upon the collapse efficiency coefficient. The erosive power term, formerly suggested as the ground component of the prediction model, is derived taking into account the damaging threshold energy of the material. An erosive efficiency coefficient is introduced on this basis that allows to quantify the erosive potential of a cavitation situation for a given material. A formula for localization of erosion is proposed that completes the prediction model. Finally, a procedure is described for geometrical scale and flow velocity transpositions.

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Jeldes, Isaac A., Daniel C. Yoder, and Eric C. Drumm. "Sustainable Slopes: Satisfying Rainfall-Erosion Equilibrium and Mechanical Stability." Transactions of the ASABE 61, no. 4 (2018): 1323–33. http://dx.doi.org/10.13031/trans.12713.

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Abstract. While manmade slopes are traditionally constructed with planar cross-sections, natural stable slopes are usually curvilinear with significant concavity of the profile. This concavity occurs as a result of evolutionary processes in which rain-driven erosion and sediment transport are balanced through slope shape adjustments. At the point of equilibrium, a relatively steady concavity with a uniform erosion rate is observed over time. Nevertheless, a true equilibrium state is possible only if mechanical stability is satisfied. In this study, concave profiles in rainfall erosion equilibrium were found based on the principles of the well-known RUSLE2 model. Results showed the existence of a family of steady shapes satisfying the condition of uniform normalized erosion rate. Those steady concave shapes that also satisfied long-term mechanical stability were then investigated. The overall results suggest that concave slopes can be constructed to achieve both minimal steady-state erosion equilibrium and mechanical stability, leading to more natural and sustainable landforms with minimal sediment delivery during initial slope adjustments. Keywords: Concave slopes, Erosion, Sustainable design, Slope stability.

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Sălcianu, Cornelia Laura, Ilare Bordeaşu, Ion Mitelea, and Lavinia Madalina Micu. "Mechanical Hardening and Resistance to Cavitation Erosion of the Austenitic Stainless Steels with Varying Proportions of Delta Ferrite." Advanced Materials Research 1111 (July 2015): 127–32. http://dx.doi.org/10.4028/www.scientific.net/amr.1111.127.

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The paper analyzes, comparative, the resistance to the cavitation erosion for the X5CrNi18-10 classic steel, with that provided by two another steels, processed experimental, with approx. 0.1 % C, 24% Cr, 18 % , approx. 10% Ni and wich was mechanically hardened by vibro rolling. Cavitation tests were performed on a vibrating device with piezoelectric crystal, in the Laboratory of Hydraulic Machines in Timisoara ( LMHT ), determining the characteristic curves of the variation in time of the mean depth erosion, MDE (t ) and mean depth erosion rate, MDER (t). By mechanical tests and by metallographic investigation is warranted increased erosion resistance after cold plastic deformation and minimization the effect of reduction its to higher proportions of delta ferrite , due to higher chromium content. Conclusions detached, after the investigations, serve designers and processors by stainless steel to chemical composition optimization and to manufacturing processes, in order to increase the lifetime of hydromechanical equipment, such as hydraulic turbines, pumps and throttle butterfly valves on pipelines forced, etc.Keywords: mechanical hardening, characteristic curves, resistance to cavitation, microstructure, chemical elements, mechanical properties

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YAMAMOTO, Mitsuru, Yukio MIYASHITA, Tohru MATSUBARA, and Tsutomu KATSUMATA. "Study on relationship between erosion characteristics and mechanical properties based on erosion mechanism." Proceedings of Conference of Hokuriku-Shinetsu Branch 2021.58 (2021): A043. http://dx.doi.org/10.1299/jsmehs.2021.58.a043.

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Selokar, Ashish, D. B. Goel, and Ujjwal Prakash. "A Comparative Study of Cavitation Erosive Behaviour of 23/8N Nitronic Steel and 13/4 Martensitic Stainless Steel." Advanced Materials Research 585 (November 2012): 554–58. http://dx.doi.org/10.4028/www.scientific.net/amr.585.554.

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Abstract: Hydroturbine blades in hydroelectric power plants are subjected to erosion. Currently these blades are made of 13/4 martensitic stainless steel (ASTM grade A743). This steel suffers from several maintenance and welding related problems. Nitronic steels are being considered as an alternative to martensitic stainless steels since they have good weldability. In present work, erosive behaviour of 13/4 Martensitic and Nitrogen alloyed austenitic stainless steel (23/8N steel) has been studied. Cavitation erosion tests were carried out in distilled water at 20 KHz frequency at constant amplitude. Microstructure of eroded surface, mechanical properties and erosion rate were characterized. It was observed that 23/8N steel possesses excellent resistance to erosion in comparison to 13/4 martensitic steels. 23/8N steel showed good hardness coupled with high tensile toughness and work hardening ability, leading to improved erosion resistance.

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Tabakoff, W., A. Hamed, and V. Shanov. "Blade Deterioration in a Gas Turbine Engine." International Journal of Rotating Machinery 4, no. 4 (1998): 233–41. http://dx.doi.org/10.1155/s1023621x98000190.

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A study has been conducted to predict blade erosion of gas turbine engines. The blade material erosion model is based on three dimensional particle trajectory simulation in the three-dimensional turbine flow field. The trajectories provide the special distribution of the particle impact parameters over the blade surface. A semi-empirical erosion model, derived from erosion tests of material samples at different particulate flow conditions, is used in the prediction of blade surface erosion based on the trajectory impact data. To improve the blade erosion resistance and to decrease the blade deterioration, the blades must be coated. For this purpose, an experimental study was conducted to investigate the behavior of rhodium platinum aluminide coating exposed to erosion by fly ash particles. New protective coatings are developed for erosion and thermal barrier. Chemical vapor deposition technique (CVD) was used to apply the ceramic TiC coatings on INCO 718 and stainless steel 410. The erosive wear of the coated samples was investigated experimentally by exposing them to particle laden flow at velocities from 180 to 305m/s and temperatures from ambient to538°C in a specially designed erosion wind tunnel. Both materials (INCO 718 and stainless steel 410) coated with CVD TiC showed one order of magnitude less erosion rate compared to some commercial coatings on the same substrates.

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Ružić, Jovana, Jelena Stašić, Dušan Božić, Marina Dojčinović, and Tatjana Volkov-Husović. "Influence of the fabrication process of copper matrix composites on cavitation erosion resistance." Metallurgical and Materials Engineering 23, no. 4 (January 9, 2018): 291–301. http://dx.doi.org/10.30544/244291.

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Copper matrix composites reinforced with ZrB2 particles were produced in two ways: by hot pressing (HP) and laser-sintering process. Powder mixture Cu-Zr-B was mechanically alloyed before densification processes. Variations in the microstructure of treated samples obtained during cavitation test were analyzed by scanning electron microscopy (SEM). Cavitation erosion resistance was investigated with the standard test method for cavitation erosion using vibratory apparatus. Changes in mechanical alloying duration show a strong influence on cavitation erosion resistance of Cu–ZrB2 composites regardless the number of reinforcements. Laser-sintered samples show better cavitation erosion resistance than hot-pressed samples.

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Bao, Ruotian, Junhong Li, Lin Li, Teresa J. Cutright, Long Chen, Jiahua Zhu, and Junliang Tao. "Effect of Microbial-Induced Calcite Precipitation on Surface Erosion and Scour of Granular Soils." Transportation Research Record: Journal of the Transportation Research Board 2657, no. 1 (January 2017): 10–18. http://dx.doi.org/10.3141/2657-02.

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Erosion is relevant to a variety of infrastructure problems such as bridge scour, roadway shoulder erosion, coastal erosion, and riverbank and slope stability. This research investigated the feasibility of using microbial-induced calcite precipitation (MICP) as an erosion countermeasure. MICP is a natural phenomenon in which calcite precipitation occurs as a consequence of microbial metabolic activity. The precipitated calcite modifies the soil fabric and provides an additional bonding force between soil particles. In this paper, a preliminary experimental study on the erosional behavior of MICP-treated sand is presented. A standard soil, Ottawa graded sand, was treated with a bacterium (Sporosarcina pasteurii) in a full-contact reactor-one in which the soil in a fabric mold was fully immersed in the bacteria and cementation solution. The morphologies and crystalline structures of the precipitated calcite in porous sediments were characterized using microscopic imaging techniques. The treated soil samples were tested in a flume to investigate the erosional behavior; both surface erosion and bridge scour tests were conducted. Although the untreated soil is highly erodible, the erosion of the treated sand was found to be negligible under the circumstances of the test; however, some concerns were raised regarding practical applications. Efforts will be made in the future to identify alternative treatment procedures that are more applicable to the field.

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GANGWAR, SWATI, VIKAS KUKSHAL, AMAR PATNAIK, and TEJ SINGH. "COMPUTATIONAL OPTIMIZATION OF TiO2 FILLED A384 ALLOY COMPOSITES IN EROSIVE ENVIRONMENT." International Journal of Computational Materials Science and Engineering 01, no. 03 (September 2012): 1250025. http://dx.doi.org/10.1142/s204768411250025x.

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In this article, micro and nano titania ( TiO2 ) filled A384 alloy composites are fabricated by stir casting technique with varying filler content from 0–8 wt.% respectively and then we study their physical, mechanical, thermal and erosive wear characteristics respectively. Effect of impact velocity (25–70 m/sec) and impingement angle (30°–90°) on erosion wear behavior of micro and nano TiO2 filled A384 alloy has also been studied. Finally, an optimization technique was implemented in order to develop a correlation between the physical, mechanical and erosion rate of TiO2 filled A384 alloy composites by using technique order preference by similarity to ideal solution (TOPSIS).

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Selokar, Ashish, Ravi Kant, D. B. Goel, and U. Prakash. "Solid Particle Erosion Behaviour of Martensitic and Nitrogen Alloyed Austenitic Stainless Steel." Advanced Materials Research 1043 (October 2014): 45–49. http://dx.doi.org/10.4028/www.scientific.net/amr.1043.45.

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In the present work, comparison of solid particle erosive behaviour of 13/4 steel and Nitrogen alloyed austenitic stainless steel (23/8N steel) have been studied using air jet erosion testing. Air jet erosion testing has been performed at various angles for as received samples at 31 m/s velocity and a discharge rate of 3 gm per minute by alumina particles with angular shape and 53-63μm size. Microstructure, eroded surface characteristics, mechanical properties and erosion rate are characterized by using scanning electron microscope, hardness and tensile testing. 23/8N steel shows good hardness coupled with high tensile toughness and work hardening ability, which leads to improved erosion resistance. The surface morphology analysis of the worn out surfaces, cumulative weight loss measurements and steady state of erosion rate results were used to understand the effect of nitrogen on the degradation mechanisms. The results show that 23/8N steel exhibits excellent resistance to erosion in comparison to13/4 steel.

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35

Zobiri, Mohamed, Mohamed Mazour, and Boutkhil Morsli. "Water erosion on marl slopes and prevention of its effects using conservation of water and soil systems in the Wadi Isser watershed – Algeria." Journal of Water and Land Development 37, no. 1 (June 1, 2018): 161–69. http://dx.doi.org/10.2478/jwld-2018-0035.

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AbstractWater erosion remains a major concern on the marly slopes. Where erosive processes continue to increase and continue to pose serious problems and where knowledge is still insufficient on erodibility and its evolution and on solutions to soil erosion problems. The aim of this work is to contribute to the understanding of the functioning of soils on marl substrate in relation to erosion and to evaluate the effectiveness of the anti-erosion measures used in this type of environment. The Isser watershed, where several anti-erosion techniques were used, is the subject of this study. The analysis of the anti-erosion installations shows that most of the developments have been made according to standards and have worked well. But their effectiveness is different from one technique to another. The earthen thresholds seem to be the most suitable and the most effective. The effectiveness of earthen structures is summed up in stability, durability, cost-effectiveness, sediment storage, flood plating and water storage for a significant length of time, and had a positive impact on reducing erosion and the silting rate of the dam. The gabion thresholds also have a better stability and a good seating, but they are very sensitive and can undergo damage that reduces their effectiveness with regard to erosion. Dry stone thresholds are the least desirable and are often inadequate and inefficient in this type of terrain. A purely mechanical and/or biological vision in this type of environment is however insufficient, the mechanical arrangements associated with the biological developments are more effective.

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Рахимов, Зиннур, Zinnur Rakhimov, Салават Мударисов, Salavat Mudarisov, Ильдар Рахимов, and Ildar Rakhimov. "EMERGENCE OF MECHANICAL SOIL EROSION ON SLOPES AND WAYS TO REDUCE IT." Vestnik of Kazan State Agrarian University 13, no. 3 (November 7, 2018): 96–102. http://dx.doi.org/10.12737/article_5bcf57a9e2e7c6.37232211.

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The work is devoted to the mathematical description of the process of occurrence and flow of mechanical soil erosion on slope fields and ways to reduce it. The dependences of mechanical erosion on the steepness of the slope, the type and parameters of the working unit, the direction of movement of the unit relative to the horizontal field are given. The obtained mathematical dependences allow us to calculate the displacement of the soil down the slope, depending on the type and parameters of the working unit and on the technology of tillage used. Purpose of the study. Reduction of mechanical soil erosion in slope fields by improving technologies and structural and technological parameters of tillage and seeding machines. Calculations showed that when the unit moves at an angle θ = 45 ÷ 70° to the horizontal of the field, the maximum displacement of the soil occurs by the lower wing of the working body (Δ1). Minimal mechanical soil erosion is provided for lancet working bodies when the unit moves relative to the horizontal of the field at an angle of 90 ± 35°, for unilateral working bodies - 120 ± 40°. It is desirable to avoid the direction of movement of the unit θ ≈ 0 ... 70°, when maximum mechanical erosion is observed when processing by one-sided working bodies (plow bodies) exceeding mechanical erosion when moving along the field horizontals 1.5 times.

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Okada, Tsunenori, Yoshiro Iwai, and Yukio Hosokawa. "Comparison of Surface Damage Caused by Sliding Wear and Cavitation Erosion on Mechanical Face Seals." Journal of Tribology 107, no. 2 (April 1, 1985): 200–205. http://dx.doi.org/10.1115/1.3261020.

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To clarify the dangerous surface damage in mechanical seals, both sliding wear and vibratory cavitation erosion tests were performed on sintered carbon materials. The differences in damage between cavitation erosion and sliding wear were investigated through observation of surface topographies and volume losses. Roughness, Ra, of worn surface is rather small, about 1 μm in the worst case, and is independent of the worn depth. In cavitation erosion, however, Ra of eroded surface increases rapidly and thereafter attains a large steady value (3.6 μm- 11 μm for various carbon materials) with increasing eroded depth regardless of the cavitation intensity. The sliding surfaces of actual operating mechanical seals were compared with our test results and thus it was concluded that the severe damage in the mechanical seals is caused by the concentrated repetition of cavitation erosion. Furthermore, the wear and cavitation erosion resistance were compared among the various carbon seal materials. From these results, it has become clear that the cavitation erosion test is important to find out the quality of mechanical seal materials.

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Sun, Jun Wei, Fu Yang Zhang, and Ping Du. "Study on Mechanical Property and Structure of Water Erosion Triple Base Propellants." Applied Mechanics and Materials 446-447 (November 2013): 1436–40. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.1436.

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The water immersion technique is conducted to increase the surface area of the triple base propellant. In order to investigate the influence of water erosion on triple base propellants, the SEM and material tester were used to observe the surface texture and test the mechanical property at different temperature .The result shows that the effect of water erosion on structure is superficial, the erosion depth is about 50~150 μm after 60 minutes,which does not impact the interior structure. The tests of mechanical property indicate that the mechanical property declines with the time of water erosion increasing, the decrease at room temperature is less than the decrease at high and low temperature.

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Mohammadi, Bijan, and AmirSajjad Khoddami. "Representative volume element-based simulation of multiple solid particles erosion of a compressor blade considering temperature effect." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 234, no. 8 (November 1, 2019): 1173–84. http://dx.doi.org/10.1177/1350650119884825.

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Solid particle erosion is one of the main failure mechanisms of a compressor blade. Thus, characterization of this damage mode is very important in life assessment of the compressor. Since experimental study of solid particle erosion needs special methods and equipment, it is necessary to develop erosion computer models. This study presents a coupled temperature–displacement finite element model to investigate damage of a compressor blade due to multiple solid particles erosion. To decrease the computational cost, a representative volume element technique is introduced to simulate simultaneous impact of multiple particles. Blade has been made of Ti-6Al-4V, a ductile titanium-based alloy, which is impacted by alumina particles. Erosion finite element modeling is assumed as a micro-scale impact problem and Johnson–Cook constitutive equations are used to describe Ti-6Al-4V erosive behavior. In regard to a wide variation range in thermal conditions all over the compressor, it is divided into three parts (first stages, middle stages, and last stages) in which each part has an average temperature. Effective parameters on erosive behavior of the blade alloy, such as impact angle, particles velocity, and particles size are studied in these three temperatures. Results show that middle stages are the most critical sites of the compressor in terms of erosion damage. An exponential relation is observed between erosion rate and particles velocity. The dependency of erosion rate on size of particles at high temperatures is indispensable.

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40

Dominguez-Cortazar, M. A., J. P. Franc, and J. M. Michel. "The Erosive Axial Collapse of a Cavitating Vortex: An Experimental Study." Journal of Fluids Engineering 119, no. 3 (September 1, 1997): 686–91. http://dx.doi.org/10.1115/1.2819299.

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The erosive efficiency of cavitating vortices is well known, although its exact mechanism has not been clarified. In order to bring fundamental information to the subject, a new device called “Cavermod” was designed in which axial collapse of a cavitating vortex is produced. We consider in this paper the design principles of the apparatus, the measurement equipment necessary for observing the phenomenon (collapse time of the order of a few milliseconds, axial collapse velocity varying between 70 and 700 m/s), and the main features of the flow. We also study the damage produced on erosion targets in order to correlate the vortex collapse with the erosion indentation features.

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Hussainova, Irina, Jakob Kubarsepp, and Juri Pirso. "Mechanical properties and features of erosion of cermets." Wear 250, no. 1-12 (October 2001): 818–25. http://dx.doi.org/10.1016/s0043-1648(01)00737-2.

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42

Schinder, Aaron M., Julian J. Rimoli, and Mitchell L. R. Walker. "Investigation of Plasma Material Erosion Under Mechanical Stress." Journal of Propulsion and Power 33, no. 2 (March 2017): 433–47. http://dx.doi.org/10.2514/1.b36253.

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Sahoo, M., A. Lui, G. Morin, and V. K. Sikka. "Mechanical Properties and Erosion Behaviour of Nickel Aluminides." Canadian Metallurgical Quarterly 30, no. 1 (January 1991): 55–69. http://dx.doi.org/10.1179/cmq.1991.30.1.55.

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44

Papamichos, Euripides. "Failure in rocks. Hydro-mechanical coupling for erosion." Revue française de génie civil 8, no. 5-6 (June 28, 2004): 709–34. http://dx.doi.org/10.3166/rfgc.8.709-734.

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45

Hussainova, Irina, Maksim Antonov, and Olga Volobueva. "Microstructural Aspects of Ceramic-Metal Composites Performance in Erosive Media." Advances in Science and Technology 45 (October 2006): 132–41. http://dx.doi.org/10.4028/www.scientific.net/ast.45.132.

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Solid particle erosion tests were conducted on WC-, TiC-, and Cr3C2 - based ceramicmetal composites (cermets) to study their performance in erosive media. The overall objectives of this study are: (i) to improve our current understanding with regards to the influence of intrinsic properties on wear behavior of cermets, (ii) to estimate an influence of metallurgical features during cermets fabrication on resistance to fracture; (iii) to consider micromechanical aspects of cermets durability; and (iiii) to offer the criteria of material reliability in different erosive conditions. For this reasons, microstructure of multiphase materials, fracture mechanisms, ability of energy dissipation and thermo-mechanical parameters and erosion resistance were analyzed.

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Boštík, Jiří, Lumír Miča, Ivailo Terzijski, Mirnela Džaferagić, and Augustin Leiter. "Grouting below Subterranean Water: Erosional Stability Test." Materials 14, no. 9 (April 30, 2021): 2333. http://dx.doi.org/10.3390/ma14092333.

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The article is focused on the medium-term negative effect of groundwater on the underground grout elements. This is the physical–mechanical effect of groundwater, which is known as erosion. We conduct a laboratory verification of the erosional resistance of grout mixtures. A new test apparatus was designed and developed, since there is no standardized method for testing at present. An erosion stability test of grout mixtures and the technical solutions of the apparatus for the test’s implementation are described. This apparatus was subsequently used for the experimental evaluation of the erosional stability of silicate grout mixtures. Grout mixtures with activated and non-activated bentonite are tested. The stabilizing effect of cellulose relative to erosion stability has been also investigated. The specimens of grout mixtures are exposed to flowing water stress for a certain period of time. The erosional stabilities of the grout mixtures are assessed on the basis of weight loss (WL) as a percentage of initial specimen weight. The lower the grout mixture weight loss, the higher its erosional stability and vice versa.

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Akhondizadeh, Mehdi, and Nader Afkhami. "Determination of erosion equation factors of AISI1020 by experimental data." Mechanics & Industry 21, no. 2 (2020): 201. http://dx.doi.org/10.1051/meca/2019087.

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Erosive wear is material removal due to the impingement of granular flow. In the present work, the effects of influencing parameters including flow velocity, incidence angle and grain size on erosive behavior of AISI1020 subjected to a flow of SiC particles has been investigated by employing an erosion wear test machine. The experiments have been performed at the different values of impact angle, flow velocity and particle size. Two tests have been performed for every set of conditions and the average of them has been presented. Results showed that the erosive wear maximizes at the impact angles of 30° and 45°. The flow of small particles resulted in more wear contrast to the large particles. Results also indicated that the influence of flow velocity was higher than the influence of impact angle and particle size. It means that minimizing the flow velocity results in more efficient results to reduce erosion. Moreover, the experimental data were used to determine appropriate coefficients for using in an erosion equation given by literature. New factors gave erosion evaluations which had appropriate accordance with the experimental data.

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Voltsihhin, Nikolai, Irina Hussainova, M. Erkin Cura, Simo Pekka Hannula, and Rainer Traksmaa. "Densification and Microstructure Development in Zirconia Toughened Hardmetals." Key Engineering Materials 527 (November 2012): 50–55. http://dx.doi.org/10.4028/www.scientific.net/kem.527.50.

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Different process methods and parameters together with different amount of additives were used to fabricate WC-Ni-ZrO2 hardmetals with mechanical properties aiming at improved performance under erosive wear. XRD observation showed the presence of tetragonal zirconia in the cermet matrix after processing. The best erosion resistance with erosion rate of about 0.7 mm3/kg was demonstrated by the specimen produced either by vacuum sintering or SPS and added by 0.2 wt% of free carbon. This cermet has also demonstrated the highest hardness of 17.7 GPa.

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Zou, Libo, Cungui Yu, Guangbin Feng, Jianlin Zhong, and Yan Lv. "Establishment of erosion model of gun steel material and study on its erosion performance." Journal of Mechanical Science and Technology 34, no. 5 (April 30, 2020): 2019–26. http://dx.doi.org/10.1007/s12206-020-0423-x.

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HATTORI, Shuji, Eisaku NAKAO, Ryu YAMAOKA, and Tsunenori OKADA. "Cavitation Erosion Mechanisms and Its Quantitative Evaluation Based on Erosion Particles." Transactions of the Japan Society of Mechanical Engineers Series A 65, no. 630 (1999): 393–99. http://dx.doi.org/10.1299/kikaia.65.393.

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Journal articles on the topic 'Mechanical erosion'

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