Two-lobe pressure dam bearings are commonly used in high speed rotating machineries. Their use is considered more stable than plain cylindrical bearings. Such bearings have a dam in the upper half whereas the lower half is provided with a relief track. Performance of two-lobe pressure dam bearings under micropolar fluid is evaluated. Finite element method is used to solve the modified Reynolds equation. Fluid film pressures are obtained by solving modified Reynolds equation. Thus pressure obtained is used to find performance characteristics of this bearing. The dynamic performance characteristics are studied at various ratios. Three ratios are considered 1.6, 2.0, and 2.4 for the analysis purpose. Results obtained are presented for various micropolar parameters. Results show that stability of two-lobe pressure dam bearings increases with decrease in aspect ratio ().
{"title":"Effect of Ratio on the Performance of Two-Lobe Pressure Dam Bearing: Micropolar Lubricated","authors":"Sanyam Sharma, C. M. Krishna","doi":"10.1155/2015/182713","DOIUrl":"https://doi.org/10.1155/2015/182713","url":null,"abstract":"Two-lobe pressure dam bearings are commonly used in high speed rotating machineries. Their use is considered more stable than plain cylindrical bearings. Such bearings have a dam in the upper half whereas the lower half is provided with a relief track. Performance of two-lobe pressure dam bearings under micropolar fluid is evaluated. Finite element method is used to solve the modified Reynolds equation. Fluid film pressures are obtained by solving modified Reynolds equation. Thus pressure obtained is used to find performance characteristics of this bearing. The dynamic performance characteristics are studied at various ratios. Three ratios are considered 1.6, 2.0, and 2.4 for the analysis purpose. Results obtained are presented for various micropolar parameters. Results show that stability of two-lobe pressure dam bearings increases with decrease in aspect ratio ().","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2015 1","pages":"1-7"},"PeriodicalIF":2.6,"publicationDate":"2015-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/182713","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64828979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The problem of couple stress squeeze films considering viscosity pressure dependence (VPD) has been analysed in a curved circular geometry. Using Stokes microcontinuum theory and the Barus formula, the Reynolds type equation has been derived. The approximate analytical expressions for the squeeze film pressure and load carrying capacity are obtained using a perturbation technique. The numerical solutions for the squeeze film pressure and load carrying capacity are presented for the sinusoidal motion of the upper curved disk, assuming an exponential form for the curvature. The effects of curvature, the non-Newtonian couple stresses, and VPD and their combined effects are investigated through the squeeze film pressure and the load carrying capacity of the squeeze film.
{"title":"Couple Stress Squeeze Films with VPD in a Curved Circular Geometry","authors":"V. Ponnuswamy, S. Govindaraj","doi":"10.1155/2015/164691","DOIUrl":"https://doi.org/10.1155/2015/164691","url":null,"abstract":"The problem of couple stress squeeze films considering viscosity pressure dependence (VPD) has been analysed in a curved circular geometry. Using Stokes microcontinuum theory and the Barus formula, the Reynolds type equation has been derived. The approximate analytical expressions for the squeeze film pressure and load carrying capacity are obtained using a perturbation technique. The numerical solutions for the squeeze film pressure and load carrying capacity are presented for the sinusoidal motion of the upper curved disk, assuming an exponential form for the curvature. The effects of curvature, the non-Newtonian couple stresses, and VPD and their combined effects are investigated through the squeeze film pressure and the load carrying capacity of the squeeze film.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2015 1","pages":"1-7"},"PeriodicalIF":2.6,"publicationDate":"2015-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/164691","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64816899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. T. Fathima, N. Naduvinamani, J. S. Kumar, B. Hanumagowda
The combined effect of surface roughness and magnetic field on the performance characteristic of the circular plates lubricated with conducting couplestress fluid (CCSF) has been studied. On the basis of the Christensen Stochastic model, the generalized stochastic Reynold’s equation is derived. Modified equations for the nondimensional pressure, load load-carrying capacity, and squeeze film time are derived. The results are presented both numerically and graphically and compared with conducting smooth surface case. It is observed that the surface roughness effects are more pronounced for couplestresses as compared to nonconducting Newtonian fluid (NCNF) in the presence of magnetic field.
{"title":"Effect of Surface Roughness on the Squeeze Film Characteristics of Circular Plates in the Presence of Conducting Couplestress Fluid and Transverse Magnetic Field","authors":"S. T. Fathima, N. Naduvinamani, J. S. Kumar, B. Hanumagowda","doi":"10.1155/2015/302396","DOIUrl":"https://doi.org/10.1155/2015/302396","url":null,"abstract":"The combined effect of surface roughness and magnetic field on the performance characteristic of the circular plates lubricated with conducting couplestress fluid (CCSF) has been studied. On the basis of the Christensen Stochastic model, the generalized stochastic Reynold’s equation is derived. Modified equations for the nondimensional pressure, load load-carrying capacity, and squeeze film time are derived. The results are presented both numerically and graphically and compared with conducting smooth surface case. It is observed that the surface roughness effects are more pronounced for couplestresses as compared to nonconducting Newtonian fluid (NCNF) in the presence of magnetic field.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"34 1","pages":"1-7"},"PeriodicalIF":2.6,"publicationDate":"2015-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/302396","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64893665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Singh, F. Gu, J. Fieldhouse, N. Singh, S. K. Singal
Automotive industries made a paradigm shift in selection of viscometrics of engine lubricant, from higher to lower viscosity grade, for improving fuel economy of vehicles. Engine fuel consumption is influenced by friction between the various engine components. Engine friction power (FP) of a direct injection diesel engine is calculated from the measured value of in-cylinder pressure signals at various operating conditions. For predicting FP, as a function of speed, load, and lubricant viscosity, a full factorial design of experiments (DOE) was formulated and an empirical correlation was developed. Response surface methodology (RSM) was used for analyzing the dominant parameters and their interactions, which influence engine friction power significantly. Predicted results of engine FP are in good agreement with measured values at all operating points. ANOVA and RSM analysis revealed that the significant parameters influencing engine FP are speed, load, viscosity, speed-load, and speed-viscosity. The effect of engine lubricant viscosity on friction power of a diesel engine was insignificant at low speed, whereas, at high speed, it played a vital role. The empirical relation developed for predicting FP is very useful in estimating engine friction power for various combinations of engine speeds, loads, and lubricant viscosity without running the engine.
{"title":"Prediction and Analysis of Engine Friction Power of a Diesel Engine Influenced by Engine Speed, Load, and Lubricant Viscosity","authors":"D. Singh, F. Gu, J. Fieldhouse, N. Singh, S. K. Singal","doi":"10.1155/2014/928015","DOIUrl":"https://doi.org/10.1155/2014/928015","url":null,"abstract":"Automotive industries made a paradigm shift in selection of viscometrics of engine lubricant, from higher to lower viscosity grade, for improving fuel economy of vehicles. Engine fuel consumption is influenced by friction between the various engine components. Engine friction power (FP) of a direct injection diesel engine is calculated from the measured value of in-cylinder pressure signals at various operating conditions. For predicting FP, as a function of speed, load, and lubricant viscosity, a full factorial design of experiments (DOE) was formulated and an empirical correlation was developed. Response surface methodology (RSM) was used for analyzing the dominant parameters and their interactions, which influence engine friction power significantly. Predicted results of engine FP are in good agreement with measured values at all operating points. ANOVA and RSM analysis revealed that the significant parameters influencing engine FP are speed, load, viscosity, speed-load, and speed-viscosity. The effect of engine lubricant viscosity on friction power of a diesel engine was insignificant at low speed, whereas, at high speed, it played a vital role. The empirical relation developed for predicting FP is very useful in estimating engine friction power for various combinations of engine speeds, loads, and lubricant viscosity without running the engine.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2014 1","pages":"928015"},"PeriodicalIF":2.6,"publicationDate":"2014-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/928015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64747406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Rajashekaraiah, Sekar Mohan, P. K. Pallathadka, Suresha Bhimappa
Various amounts of short fibers (glass and carbon) and particulate fillers like polytetrafluoroethylene (PTFE), silicon carbide (SiC), and alumina (Al2O3) were systematically introduced into the thermoplastic copolyester elastomer (TCE) matrix for reinforcement purpose. The mechanical properties such as storage modulus, loss modulus, and Tan δ by dynamic mechanical analysis (DMA) and three-body abrasive wear performance on a dry sand rubber wheel abrasion tester have been investigated. For abrasive wear study, the experiments were planned according to orthogonal array by considering three factors and three levels. The complex moduli for TCE hybrid composites were pushed to a higher level relative to the TCE filled PTFE composite. At lower temperatures (in the glassy region), the storage modulus increases with increase in wt.% of reinforcement (fiber
{"title":"Dynamic Mechanical Analysis and Three-Body Abrasive Wear Behaviour of Thermoplastic Copolyester Elastomer Composites","authors":"H. Rajashekaraiah, Sekar Mohan, P. K. Pallathadka, Suresha Bhimappa","doi":"10.1155/2014/210187","DOIUrl":"https://doi.org/10.1155/2014/210187","url":null,"abstract":"Various amounts of short fibers (glass and carbon) and particulate fillers like polytetrafluoroethylene (PTFE), silicon carbide (SiC), and alumina (Al2O3) were systematically introduced into the thermoplastic copolyester elastomer (TCE) matrix for reinforcement purpose. The mechanical properties such as storage modulus, loss modulus, and Tan δ by dynamic mechanical analysis (DMA) and three-body abrasive wear performance on a dry sand rubber wheel abrasion tester have been investigated. For abrasive wear study, the experiments were planned according to orthogonal array by considering three factors and three levels. The complex moduli for TCE hybrid composites were pushed to a higher level relative to the TCE filled PTFE composite. At lower temperatures (in the glassy region), the storage modulus increases with increase in wt.% of reinforcement (fiber","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2014 1","pages":"1-14"},"PeriodicalIF":2.6,"publicationDate":"2014-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/210187","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64389281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Molina, Fnu Aktaruzzaman, Whitney Stregles, V. Soloiu, Mosfequr Rahman
Nanofluids are nanosize-powder suspensions that are of interest for their enhanced thermal transport properties. They are studied as promising alternatives to ordinary cooling fluids, but the tribiological effects of nanofluids on cooling-system materials are largely unknown. The authors have developed methodology that uses jet impingement on typical cooling-system materials to test such effects. The work is presented of the authors’ research on the interactions of a typical nanofluid (2% volume of alumina nanopowders in a solution of ethylene glycol in water) which is impinged on aluminum and copper specimens for tests as long as 112 hours. The surface changes were assessed by roughness measurements and optical-microscope studies. Comparative roughness indicate that both the reference cooling fluid of ethylene glycol and water and its nanofluid with 2% alumina produce roughness changes in aluminum (even for the shortest 3-hour test), but no significant roughness differences were observed between them. No significant roughness changes were observed for copper. Microscopy observations, however, show different surface modifications in both aluminum and copper by both the nanofluid and its base fluid. The possible mechanisms of early erosion are discussed. These investigations demonstrate suitable methods for the testing of nanofluid effects on cooling system-materials.
{"title":"Jet-Impingement Effects of Alumina-Nanofluid on Aluminum and Copper","authors":"G. Molina, Fnu Aktaruzzaman, Whitney Stregles, V. Soloiu, Mosfequr Rahman","doi":"10.1155/2014/476175","DOIUrl":"https://doi.org/10.1155/2014/476175","url":null,"abstract":"Nanofluids are nanosize-powder suspensions that are of interest for their enhanced thermal transport properties. They are studied as promising alternatives to ordinary cooling fluids, but the tribiological effects of nanofluids on cooling-system materials are largely unknown. The authors have developed methodology that uses jet impingement on typical cooling-system materials to test such effects. The work is presented of the authors’ research on the interactions of a typical nanofluid (2% volume of alumina nanopowders in a solution of ethylene glycol in water) which is impinged on aluminum and copper specimens for tests as long as 112 hours. The surface changes were assessed by roughness measurements and optical-microscope studies. Comparative roughness indicate that both the reference cooling fluid of ethylene glycol and water and its nanofluid with 2% alumina produce roughness changes in aluminum (even for the shortest 3-hour test), but no significant roughness differences were observed between them. No significant roughness changes were observed for copper. Microscopy observations, however, show different surface modifications in both aluminum and copper by both the nanofluid and its base fluid. The possible mechanisms of early erosion are discussed. These investigations demonstrate suitable methods for the testing of nanofluid effects on cooling system-materials.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2014 1","pages":"1-8"},"PeriodicalIF":2.6,"publicationDate":"2014-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/476175","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64510452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Fellah, M. Labaiz, O. Assala, L. Dekhil, A. Taleb, Hadda Rezag, A. Iost
The aim of the study is to evaluate the friction and wear behavior of high-strength alloys Ti-6Al-7Nb used in femoral stem and compare it with a Ti-6Al-4V alloy cylindrical bar corresponding to ISO 5832-3 part 3/01-07-199 standard. The tribological behavior was investigated by wear tests, using ball-on-disc and pin-on-disc tribometers. These tests consisted of measuring the weight loss and the friction coefficient of samples. The oscillating friction and wear tests have been carried out in ambient with oscillating tribotester in accordance with standards ISO 7148, ASTM G99-95a, and ASTM G133-95 under different conditions of normal loads (3, 6, and 10 N) and sliding speeds (1, 15, and 25 mm·s−1). As counter pairs, a 100Cr6 steel ball with 10 mm in diameter was used. Results show that the two alloys had similar friction and wear performance, although their grain structures and compositions are different. Occurrence of large frictional occurred, is probably caused by formation and periodic, localized fracture of a transfer layer. Higher friction with larger fluctuation and higher wear rate was observed at the higher siding speed. The Ti-6Al-4V wear mechanism transforms from ploughing and peeling off wear at low sliding speed to plastic deformation and adhesive wear.
本研究的目的是评价股骨干用高强度合金Ti-6Al-7Nb的摩擦磨损性能，并将其与符合ISO 5832-3 part 3/01-07-199标准的Ti-6Al-4V合金圆柱棒进行比较。通过使用球盘式和销盘式摩擦计进行磨损试验，研究了其摩擦学行为。这些试验包括测量试样的失重和摩擦系数。根据ISO 7148、ASTM G99-95a和ASTM G133-95标准，在正常载荷(3、6和10 N)和滑动速度(1、15和25 mm·s−1)的不同条件下，在环境中使用振动摩擦试验机进行了振动摩擦和磨损试验。作为计数器对，使用直径为10mm的100Cr6钢球。结果表明，两种合金具有相似的摩擦磨损性能，但晶粒组织和成分不同。大摩擦发生的发生，可能是由传递层的形成和周期性、局部性断裂引起的。当侧壁速度越高时，摩擦强度越大，波动越大，磨损率越高。Ti-6Al-4V磨损机制由低滑动速度下的犁耕剥落磨损转变为塑性变形和黏着磨损。
{"title":"Tribological behavior of Ti-6Al-4V and Ti-6Al-7Nb Alloys for Total Hip Prosthesis","authors":"M. Fellah, M. Labaiz, O. Assala, L. Dekhil, A. Taleb, Hadda Rezag, A. Iost","doi":"10.1155/2014/451387","DOIUrl":"https://doi.org/10.1155/2014/451387","url":null,"abstract":"The aim of the study is to evaluate the friction and wear behavior of high-strength alloys Ti-6Al-7Nb used in femoral stem and compare it with a Ti-6Al-4V alloy cylindrical bar corresponding to ISO 5832-3 part 3/01-07-199 standard. The tribological behavior was investigated by wear tests, using ball-on-disc and pin-on-disc tribometers. These tests consisted of measuring the weight loss and the friction coefficient of samples. The oscillating friction and wear tests have been carried out in ambient with oscillating tribotester in accordance with standards ISO 7148, ASTM G99-95a, and ASTM G133-95 under different conditions of normal loads (3, 6, and 10 N) and sliding speeds (1, 15, and 25 mm·s−1). As counter pairs, a 100Cr6 steel ball with 10 mm in diameter was used. Results show that the two alloys had similar friction and wear performance, although their grain structures and compositions are different. Occurrence of large frictional occurred, is probably caused by formation and periodic, localized fracture of a transfer layer. Higher friction with larger fluctuation and higher wear rate was observed at the higher siding speed. The Ti-6Al-4V wear mechanism transforms from ploughing and peeling off wear at low sliding speed to plastic deformation and adhesive wear.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2014 1","pages":"1-13"},"PeriodicalIF":2.6,"publicationDate":"2014-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/451387","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64497237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Combined effects of surface roughness and viscosity-pressure dependency on the couple stress squeeze film characteristics of parallel circular plates are presented. On the basis of Christensen’s stochastic theory, two types of one-dimensional roughness structures, namely, the radial roughness and azimuthal roughness patterns, are considered and the stochastic modified Reynolds equation for these two types of roughness patterns is derived for Stokes couple stress fluid by taking into account variation of viscosity with pressure. The standard perturbation technique is employed to solve the averaged Reynolds equation and closed form expressions for the mean fluid film pressure, load carrying capacity, and squeeze film time are obtained. It is found that the effects of couple stresses and viscosity-pressure dependency are to increase the load carrying capacity, and squeeze film time for both types of roughness patterns. The effect of azimuthal (radial) roughness pattern is to increase (decrease) these squeeze film characteristics as compared to the corresponding smooth case.
{"title":"Effect of Surface Roughness and Viscosity-Pressure Dependency on the Couple Stress Squeeze Film Characteristics of Parallel Circular Plates","authors":"N. Naduvinamani, S. Apparao, Ayyappa G. Hiremath","doi":"10.1155/2014/387413","DOIUrl":"https://doi.org/10.1155/2014/387413","url":null,"abstract":"Combined effects of surface roughness and viscosity-pressure dependency on the couple stress squeeze film characteristics of parallel circular plates are presented. On the basis of Christensen’s stochastic theory, two types of one-dimensional roughness structures, namely, the radial roughness and azimuthal roughness patterns, are considered and the stochastic modified Reynolds equation for these two types of roughness patterns is derived for Stokes couple stress fluid by taking into account variation of viscosity with pressure. The standard perturbation technique is employed to solve the averaged Reynolds equation and closed form expressions for the mean fluid film pressure, load carrying capacity, and squeeze film time are obtained. It is found that the effects of couple stresses and viscosity-pressure dependency are to increase the load carrying capacity, and squeeze film time for both types of roughness patterns. The effect of azimuthal (radial) roughness pattern is to increase (decrease) these squeeze film characteristics as compared to the corresponding smooth case.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2014 1","pages":"1-7"},"PeriodicalIF":2.6,"publicationDate":"2014-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/387413","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64473939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Solid particle erosion (SPE) tests are carried out to evaluate the performance of plasma sprayed coatings of borosilicate glass microspheres (BGM) premixed with Al2O3 particles on metallic substrates. For this purpose, an Air Jet Erosion test rig confirming to ASTM G 76 test standards is used. Relative influence of different operating parameters on erosion rate is assessed by statistical analysis of the experimental findings that are based on Taguchi’s L16 orthogonal array. This analysis helps to identify the most significant factor affecting the erosion wear rate of the coating. The study reveals that the impact velocity, impingement angle, erodent size, and Al2O3 content in the feed stock, in the declining sequence, are the significant factors influencing the wear rate of these coatings. An Artificial Neural Network (ANN) approach is then implemented taking into account training and test procedure to predict the triboperformance of these coatings under wear conditions beyond the experimental range. Further, the microstructural features of the eroded samples are studied from SEM images to identify possible wear mechanisms.
采用固相颗粒侵蚀(SPE)试验评价了硼硅酸盐玻璃微球(BGM)与Al2O3颗粒预混在金属基体上的等离子喷涂涂层的性能。为此，使用符合ASTM G 76测试标准的空气射流侵蚀试验台。通过对基于田口L16正交试验结果的统计分析，评价了不同操作参数对侵蚀速率的相对影响。这种分析有助于确定影响涂层侵蚀磨损率的最重要因素。研究表明，冲击速度、冲击角、侵蚀尺寸和进料中Al2O3含量依次递减是影响涂层磨损率的重要因素。然后采用人工神经网络(ANN)方法，结合训练和测试过程来预测这些涂层在超出实验范围的磨损条件下的摩擦性能。此外，从扫描电镜图像中研究侵蚀样品的微观结构特征，以确定可能的磨损机制。
{"title":"Studies on Erosion Behavior of Plasma Sprayed Coatings of Glass Microspheres Premixed with Al2O3 Particles","authors":"G. Gupta, A. Satapathy","doi":"10.1155/2014/763601","DOIUrl":"https://doi.org/10.1155/2014/763601","url":null,"abstract":"Solid particle erosion (SPE) tests are carried out to evaluate the performance of plasma sprayed coatings of borosilicate glass microspheres (BGM) premixed with Al2O3 particles on metallic substrates. For this purpose, an Air Jet Erosion test rig confirming to ASTM G 76 test standards is used. Relative influence of different operating parameters on erosion rate is assessed by statistical analysis of the experimental findings that are based on Taguchi’s L16 orthogonal array. This analysis helps to identify the most significant factor affecting the erosion wear rate of the coating. The study reveals that the impact velocity, impingement angle, erodent size, and Al2O3 content in the feed stock, in the declining sequence, are the significant factors influencing the wear rate of these coatings. An Artificial Neural Network (ANN) approach is then implemented taking into account training and test procedure to predict the triboperformance of these coatings under wear conditions beyond the experimental range. Further, the microstructural features of the eroded samples are studied from SEM images to identify possible wear mechanisms.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2014 1","pages":"1-11"},"PeriodicalIF":2.6,"publicationDate":"2014-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/763601","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64661565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aluminium-graphite composites were synthesized using powder metallurgy route. Graphite was added as reinforcement in the range of 0, 3, and 6 weight % and composites were prepared by P/M. Microstructural analysis of the newly synthesized composites was carried out using SEM. The hardness of the composites was studied using Vickers microhardness tester, by applying a load of 1 kg for 5 sec. Also the amount of porosity was determined. Further the wear test was conducted on the sintered specimens using pin-on-disc wear apparatus according to ASTM-G99 standards. A regression model was developed to predict the wear rate of the specimen. Then the worn images were studied using SEM based on response surface methodology in order to understand the various wear mechanisms involved. The study revealed that mild wear, oxidational wear, plowing, cutting, and plastic deformation are the main mechanisms responsible for causing the wear.
{"title":"Characterization and Empirical Modelling of Sliding Wear on Sintered Aluminium-Graphite Composites","authors":"Amrishraj Doraisamy, S. Thiagarajan","doi":"10.1155/2014/273738","DOIUrl":"https://doi.org/10.1155/2014/273738","url":null,"abstract":"Aluminium-graphite composites were synthesized using powder metallurgy route. Graphite was added as reinforcement in the range of 0, 3, and 6 weight % and composites were prepared by P/M. Microstructural analysis of the newly synthesized composites was carried out using SEM. The hardness of the composites was studied using Vickers microhardness tester, by applying a load of 1 kg for 5 sec. Also the amount of porosity was determined. Further the wear test was conducted on the sintered specimens using pin-on-disc wear apparatus according to ASTM-G99 standards. A regression model was developed to predict the wear rate of the specimen. Then the worn images were studied using SEM based on response surface methodology in order to understand the various wear mechanisms involved. The study revealed that mild wear, oxidational wear, plowing, cutting, and plastic deformation are the main mechanisms responsible for causing the wear.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":"2014 1","pages":"1-8"},"PeriodicalIF":2.6,"publicationDate":"2014-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/273738","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64417889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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