Al2O3-coated h-BN composite powders and as-prepared Si3N4-based self-lubricating ceramic cutting tool material. (February 2018)

• Record Type: Journal Article
• Authors: Zhang, Wenliang; Yi, Mingdong; Xiao, Guangchun; Ma, Jun; Wu, Guangyong; Xu, Chonghai
• Is Part Of: International journal of refractory metals & hard materials. Volume 71(2018)
• Page Start: 1
• Page End: 7
• Publication Date: 2018-02
• Subjects: Surface coating modification -- Heterogeneous nucleation process -- Self-lubricating -- Si3N4 ceramic cutting tool; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2017.10.018
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: The surfaces of solid lubricant hexagonal boron nitride (h-BN) powders were coated with compacted and integrated Al(OH)3 by heterogeneous nucleation and then the h-BN@Al2 O3 composite powders were prepared by calcination under vacuum at 1200 °C for 2 h, as determined by SEM, EDS and XRD. The Si3 N4 self-lubricating ceramic cutting tool material with coated h-BN was prepared by vacuum hot pressing. Microstructure analysis showed that the h-BN@Al2 O3 particles 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·m 1/2, 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 Si3 N4 /TiC/(h-BN@Al2 O3 ) self-lubricating ceramic cutting tool had better antifriction property and wear resistance than the corresponding cutting tool. Highlights: A cutting tool material with addition of metallic oxide coated solid lubricant was proposed. Si3 N4 /TiC/(h-BN@Al2 O3 ) cutting tool material was prepared by hot pressing process. The as-prepared material has better mechanical properties and cutting performance.