标题：Al2O3-coated h-BN composite powders and as-prepared Si3N4-based self-lubricating ceramic cutting tool material
作者：Zhang, Wenliang ;Yi, Mingdong ;Xiao, Guangchun ;Ma, Jun ;Wu, Guangyong ;Xu, Chonghai
作者机构：[Zhang, Wenliang ;Yi, Mingdong ;Xiao, Guangchun ;Ma, Jun ;Wu, Guangyong ;Xu, Chonghai ] School of Mechanical and Automotive Engineering, Qilu Universi 更多
来源：International Journal of Refractory Metals and Hard Materials
摘要：The surfaces of solid lubricant hexagonal boron nitride (h-BN) powders were coated with compacted and integrated Al(OH)3by heterogeneous nucleation and then the h-BN@Al2O3composite powders were prepared by calcination under vacuum at 1200 °C for 2 h, as determined by SEM, EDS and XRD. The Si3N4self-lubricating ceramic cutting tool material with coated h-BN was prepared by vacuum hot pressing. Microstructure analysis showed that the h-BN@Al2O3particles were dispersed homogeneously in the matrix and that the particles were tightly bound. Vickers hardness was 14.1 GPa, fracture toughness was 7.2 MPa·m1/2, and flexural strength was 732 MPa, as determined by mechanical property testing. The hardness, fracture toughness, and flexural strength of the material were increased by 27.0%, 5.9% and 22.2%, respectively, relative to the material to which uncoated h-BN was added. Cutting tests showed that the Si3N4/TiC/(h-BN@Al2O3) self-lubricating ceramic cutting tool had better antifriction property and wear resistance than the corresponding cutting tool.
© 2017 Elsevier Ltd