Wear of structural oxide ceramics produced through additive manufacturing

Ceramics have exceptional tribological performance in high wear applications, but susceptibility to brittle fracture requires expensive post-processing, including hot isostatic pressing and polishing. Consequently, additive manufacturing (AM) represents a collection of potentially cost-saving approaches for ceramic production. AM technologies have been demonstrated for oxide ceramics, but the performance of self-mated AM materials remains unknown and underscores a critical knowledge gap. Alumina and zirconia pins produced with photo-polymerization, binder-jetting, or material-jetting were obtained. For each fabrication method, the average wear coefficient was determined using pin-on-disk testing. Conventionally pressed and sintered ceramics were applied as counterface surfaces and controls. The manufacturing approach did not demonstrate differences in wear coefficient for zirconia. However, photopolymerized alumina was shown to outperform material-matched binder-jetted and conventional pin-disk tribopairs. Starting surface roughness and bulk density were found to correlate volumetric wear. Characterization of the AM ceramics revealed that photo-polymerization and material jetting were capable of dense and refined microstructures. Evaluations indicate that ceramics produced with photo-polymerization and certain powder-bed AM approaches meet and exceed conventional ceramics, supporting the expansion of AM ceramic applications. (C) 2019 The Authors. Published by Elsevier B.V.