Acoustic emission characterization of sliding wear under condition of direct and inverse transformations in lowtemperature degradation aged Y-TZP and Y-TZP-Al_2O_3  

作　　者：Nikolai L SAVCHENKO Andrey V FILIPPOV Sergei Yu TARASOV Andrey I DMITRIEV Evgeny V SHILKO Aleksandr S GRIGORIEV 

机构地区：[1]Institute of Strength Physics and Materials Science SB RAS [2]National Research Tomsk Polytechnic University [3]National Research Tomsk State University

出　　处：《Friction》2018年第3期323-340,共18页摩擦（英文版）

基　　金：financially supported by the Russian Federation via the Ministry of Education and Science of the Russian Federation (Agreement No. 14.607.21.0186, project identifier RFMEFI60717X0186)

摘　　要：In this research, results of the investigation of the sliding friction and wear of yttria-stabilized tetragonal zirconia polycrystalline(Y-TZP) and Y-TZP-Al_2O_3 samples preliminarily subjected to low-temperature degradation are reported. The investigation was carried out using a pin-on-disk tribometer with simultaneous recording of acoustic emission(AE) and vibration acceleration. The sliding wear process was found to be determined by dynamic direct and inverse Y-TZP transformations detected by monoclinic and tetragonal X-ray diffraction peak ratios. The AE signals generated under direct and inverse transformations can be used to characterize wear and friction mechanisms as well as direct and inversed sliding-induced phase transformations. The AE signal energy grows with the friction coefficient and the inverse transformation degree. Reduction of the AE signal energy indicates establishing the mild wear stage caused by effective stress-induced direct martensitic transformation. The AE signal median frequency increases in the case of lower friction. Numerical studies of wear subsurface fracture under conditions of stress-induced martensitic transformation were used to elucidate the role played by the phase transformation in Y-TZP and Y-TZP-Al_2O_3. Martensitic transformation in Y-TZP was described with use of the non-associated dilatant plasticity model. Simulation results particularly show that increase in the value of dilatancy coefficient from 0 to 0.2 is accompanied by 25%-30% reduce in characteristic length and penetration depth of sliding-induced subsurface cracks. As shown the AE may be an effective tool for in-situ monitoring the subsurface wear of materials experiencing both direct and inverse transformations.In this research, results of the investigation of the sliding friction and wear of yttria-stabilized tetragonal zirconia polycrystalline （Y-TZP） and Y-TZP-Al2O3 samples preliminarily subjected to low-temperature degradation are reported. The investigation was carried out using a pin-on-disk tribometer with simultaneous recording of acoustic emission （AE） and vibration acceleration. The sliding wear process was found to be determined by dynamic direct and inverse Y-TZP transformations detected by monoclinic and tetragonal X-ray diffraction peak ratios. The AE signals generated under direct and inverse transformations can be used to characterize wear and friction mechanisms as well as direct and inversed sliding-induced phase transformations. The AE signal energy grows with the friction coefficient and the inverse transformation degree. Reduction of the AE signal energy indicates establishing the mild wear stage caused by effective stress-induced direct martensitic transformation. The AE signal median frequency increases in the case of lower friction. Numerical studies of wear subsurface fracture under conditions of stress-induced martensitic transformation were used to elucidate the role played by the phase transformation in Y-TZP and Y-TZP-Al2O3. Martensitic transformation in Y-TZP was described with use of the non-associated dilatant plasticity model. Simulation results particularly show that increase in the value of dilatancy coefficient from 0 to 0.2 is accompanied by 25%-30% reduce in characteristic length and penetration depth of sliding-induced subsurface cracks. As shown the AE may be an effective tool for in-situ monitoring the subsurface wear of materials experiencing both direct and inverse transformations.

关 键 词：ZIRCONIA transformation toughening low-temperature degradation FRICTION acoustic emission numerical modeling movable cellular automata method 

分 类 号：TS103.63[轻工技术与工程—纺织工程] TD355.47[轻工技术与工程—纺织科学与工程]