Acoustic emission characterization of sliding wear under condition of direct and inverse transformations in low-temperature degradation aged Y-TZP and Y-TZP-AL2O3

Abstract

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 2 O 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 2 O 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.

Modeling Wear and Friction Regimes on Ceramic Materials with Positive and Negative Thermal Expansion

“…The results of modeling are consistent with those obtained from experiments that are not just qualitative. In particular, COF values in the range 0.3-0.4 were obtained on ZrO2 using a pin-on-disk scheme and both sliding speed and pressures close to those used in this work [63].…”

The Effect of Ultrafine-Grained (UFG) Structure Formed by Equal-Channel Angular Pressing in AA7075 on Wear and Friction in Sliding against Steel and Ceramic Counterbodies

“…It was discovered earlier [44][45][46][47] that AE characteristics such as median frequency and energy are the most informative ones when used for studying fast-occurring processes such as metal cutting, where friction is an integral feature. The mean values of these characteristics are convenient means for assessing the sensitivity of the wear and friction to the structural states of the materials in rubbing, as demonstrated by the results shown in Figure 9.…”

MEZOSKOPIChESKAYa MODEL'' TRENIYa ALYuMINIEVOY BRONZY NA OSNOVE METODA PODVIZhNYKh KLETOChNYKh AVTOMATOV

“…Дальнейшее развитие модели заключалось в создании трѐхмерных образцов и моделировании сжатия, индентирования и трения композиционных образцов на основе алюминиевой бронзы с упрочняющими включениями карбида бора. Кроме того, предложены критерии и способ учѐта возможных мартенситных превращений в алюминиевой бронзе на основе дилатансионной модели пластичности [4]. В результаты выполненных исследований показано, что разработанная модель позволяет исследовать влияние локальных структурных превращений на поведение поверхностных слоѐв алюминиевой бронзы в условиях интенсивного трения, и способна учитывать эффекты разрушения, массопереноса и перемешивания, а также адгезионное взаимодействие поверхностей.…”