Microstructure and mechanical properties of WC–Ni multiphase ceramic materials with NiCl 2 ·6H 2 O as a binder

Nanotechnology Reviews

article

Xingxing Lyu¹  Xiaosong Jiang¹  Hongliang Sun¹  Zhenyi Shao¹ 

[1] Key Laboratory of Advanced Technologies of Materials, Ministry of Education;School of Materials Science and Engineering, Southwest Jiaotong University

关键词: WC–Ni composite ceramics;    hot isostatic pressing;    densification;   

DOI  :  10.1515/ntrev-2020-0044

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

High-density WC–Ni composite ceramics were prepared by cold isostatic pressing–vacuum pressureless sintering–hot isostatic pressing with tungsten carbide (WC) powder and NiCl 2 ·6H 2 O as a binder. Results show that with an increase in the contents of Ni in the metal binder phase, the relative density of WC–Ni composite ceramics is improved, and the formation of the carbon-deficient W 2 C phase is reduced. There is no W 2 C generated in the WC–1 wt% Ni material. At high temperatures, the Ni phase changes into the liquid phase and enters between the WC particles, thereby promoting the close alignment of the WC particles. Moreover, the WC particles will be more closely aligned under their own surface tension and capillary action, thereby promoting the densification of WC–Ni composite ceramics. The WC–0.5 wt% Ni composite ceramics are fully dense and show the best comprehensive performance with a microhardness of 23.0 GPa, a fracture toughness of 5.28 MPa m 1/2 , and a flexural strength of 1,396.58 MPa. WC–Ni composite ceramics are mainly composed of elongated triangular prism WC particles and Ni phase. Transgranular fracture was the main fracture mode of WC–Ni multiphase ceramic materials with a small amount of intergranular fracture due to the existence of the Ni phase. Such a fracture mode can increase the flexural strength of the composite material.

【 授权许可】

CC BY