An innovative physical simulation apparatus, including high speed camera, red thermal imaging system, and mechanical quantity sensor, was used to investigate the friction heat generation and atom diffusion behavior du...An innovative physical simulation apparatus, including high speed camera, red thermal imaging system, and mechanical quantity sensor, was used to investigate the friction heat generation and atom diffusion behavior during Mg-Ti friction welding process. The results show that the friction coefficient mainly experiences two steady stages. The first steady stage corresponds to the Coulomb friction with material abrasion. The second steady stage corresponds to the stick friction with fully plastic flow. Moreover, the increasing rates of axial displacement, temperature and friction coefficient are obviously enhanced with the increase of rotation speed and axial pressure. It can also be found that the there exists rapid diffusion phenomenon in the Mg-Ti friction welding system. The large deformation activated diffusion coefficient is about 105 higher than that activated by thermal.展开更多
Non lubricated slide performance of functional grade copper matrix composite,fabricated using horizontal centrifuge cast technique was investigated using pin-on-disc tribo-tester.Rate of wear and friction coefficient ...Non lubricated slide performance of functional grade copper matrix composite,fabricated using horizontal centrifuge cast technique was investigated using pin-on-disc tribo-tester.Rate of wear and friction coefficient of the inner wall thickness of hollow cylindrical cast specimen was analyzed using Taguchi based L27 orthogonal array,where the percentage of graphite particles were observed higher.Variable process parameters those influenced the rate of wear directly or indirectly were:applied load(15,25 and 35 N),slide velocity(1.5,2.5 and 3.5 m/s)and slide distance(750,1500 and 2250 m).Rate of wear and friction coefficient showed a proportional dependency with applied load and slide distance,whereas showing a decline during intermediate slide velocity.Signal-to-Noise ratio predicted the minimal tribo-condition,on‘smaller-the-better’basis.Analysis of Variance technique quantified the influence of affecting parameters,along with their interactions.Regression analysis was utilized for the validation of the experimental data.Micrographs and scanning electron microscopy exhibited the wear mechanisms and mechanically mixed layer formation during worn surfaces analysis.展开更多
基金Projects (51101126, 51071123) supported by the National Natural Science Foundation of ChinaProjects (20110491684, 2012T50817) supported by the China Postdoctoral Science FoundationProject (20110942K) supported by the Open Fund of State Key Laboratory of Powder Metallurgy of Central South University, China
文摘An innovative physical simulation apparatus, including high speed camera, red thermal imaging system, and mechanical quantity sensor, was used to investigate the friction heat generation and atom diffusion behavior during Mg-Ti friction welding process. The results show that the friction coefficient mainly experiences two steady stages. The first steady stage corresponds to the Coulomb friction with material abrasion. The second steady stage corresponds to the stick friction with fully plastic flow. Moreover, the increasing rates of axial displacement, temperature and friction coefficient are obviously enhanced with the increase of rotation speed and axial pressure. It can also be found that the there exists rapid diffusion phenomenon in the Mg-Ti friction welding system. The large deformation activated diffusion coefficient is about 105 higher than that activated by thermal.
文摘Non lubricated slide performance of functional grade copper matrix composite,fabricated using horizontal centrifuge cast technique was investigated using pin-on-disc tribo-tester.Rate of wear and friction coefficient of the inner wall thickness of hollow cylindrical cast specimen was analyzed using Taguchi based L27 orthogonal array,where the percentage of graphite particles were observed higher.Variable process parameters those influenced the rate of wear directly or indirectly were:applied load(15,25 and 35 N),slide velocity(1.5,2.5 and 3.5 m/s)and slide distance(750,1500 and 2250 m).Rate of wear and friction coefficient showed a proportional dependency with applied load and slide distance,whereas showing a decline during intermediate slide velocity.Signal-to-Noise ratio predicted the minimal tribo-condition,on‘smaller-the-better’basis.Analysis of Variance technique quantified the influence of affecting parameters,along with their interactions.Regression analysis was utilized for the validation of the experimental data.Micrographs and scanning electron microscopy exhibited the wear mechanisms and mechanically mixed layer formation during worn surfaces analysis.
