Fretting fatigue wear behavior of Y‐TZP dental ceramics processed by non‐conventional microwave sintering

Abstract

The fretting wear behavior of self‐mated Y‐TZP dental materials obtained by nonconventional microwave and conventional sintering has been investigated. Two 3Y‐TZP materials, a widely utilized commercial dental ceramic (LAVA) and a lab‐prepared 3Y‐TZP powder based equivalent have been assessed. Relative density and mechanical properties as well as the grain size variations upon sintering have been evaluated. After exposure to selected gross slip regime fretting wear conditions, the wear tracks have been characterized allowing the measurement of the coefficient of friction, track profiles, and pit features. The results indicate that microwave sintering results in a similar fretting wear behavior as observed for conventional‐sintered 3Y‐TZP, as the measured volumetric wear loss is of a comparable order of magnitude. Regarding the influence of the grain size, the analysis revealed that a large grain size (>300 nm) results in an increased wear volume and that a higher resistance to fretting wear is constrained to a mid‐range particle size (100–250 nm). Since the fracture toughness of all investigated ceramic grades was comparable, the influence of the fracture toughness on fretting could not be assessed. Abrasive grooving, delamination, and microcracking have been identified as major wear mechanisms inside the wear tracks for both conventional‐ and microwave‐sintered 3Y‐TZP. In general, microwave sintering can provide 3Y‐TZP dental materials with a comparable fretting wear resistance as that observed for conventional sintering using lower dwell sintering temperatures and a shorter processing time.

Advanced Ceramic Materials Sintered by Microwave Technology

“…In general, the study suggests that microwave sintering of zirconia can result in comparable mechanical properties and high degrees of densification comparable to those achieved with conventional sintering systems at lower dwell temperatures and significantly shorter sintering times [50][51][52][53][54]. Moreover, some studies have demonstrated that microwave-sintered specimens exhibit enhanced crystallinity [55] and improved mechanical properties [18,49,56].…”

Effect of sintering duration on the sliding‐wear resistance of 3Y‐TZP dental ceramics

“…19,29,30 Sliding moves the microcontacts along, thus resulting in the observed scratches. 18,25,[31][32][33] Such spalling is particularly deleterious, since the greater surface roughness of the exposed regions may also damage the counterbody-in the oral cavity this can result in wear of antagonist teeth. The microcracks are randomly oriented, and not observed to be accompanied by transformation to the monoclinic phase, which indeed, inside the scars, was not observed at all.…”

“…The microcracks are randomly oriented, and not observed to be accompanied by transformation to the monoclinic phase, which indeed, inside the scars, was not observed at all. [23][24][25][26][27][31][32][33][36][37][38] , with pitting from particle pull-out indicated in Refs. 29 In some isolated regions of the wear scars, exposed patches of major roughness can also be observed ( Figure 8C).…”

“…These are attributable to the coalescence of sub-surface cracks in zones that contain a high density of microwear markings, thus leading to the formation of larger wear particles, or spalling. 18,25,[31][32][33] Such spalling is particularly deleterious, since the greater surface roughness of the exposed regions may also damage the counterbody-in the oral cavity this can result in wear of antagonist teeth. 34,35 The observation of both plastic deformation and fracture wear mechanisms is consistent with the value obtained for the specific wear rate, which was at the boundary between mild and severe wear, since plastic deformation alone is typically associated with mild wear, and fracture with severe wear.…”

Study on tribo-chemical and fatigue behavior of 316L austenitic stainless steel in torsional fretting fatigue

“…[2][3][4][5][6] In the fretting fatigue failure process, combining action with the fatigue behavior and wear damage of interface surfaces, it leads to the component occurring fatigue crack initiation, propagation and final failure. [7][8][9] Therefore, the objective of this work is to further study on tribo-chemical and fatigue behavior of torsional fretting fatigue. In addition, the frictional behavior in the fretting process is also discussed.…”