Comparative Study on Microstructure and Mechanical Properties of Coarse-grained WC-based Cemented Carbides Sintered with Ultrafine WC or (W+C) as Additives.

Autor: Yu, Songbai, Min, Fanlu, Li, De, Noudem, Guillaume Jacques, Zhang, Hailong, Ma, Jichang, Zhao, Kui, Yao, Zhanhu, Zhang, Jianfeng
Zdroj: Journal of Wuhan University of Technology; Apr2024, Vol. 39 Issue 2, p399-409, 11p
Abstrakt: The effects of ultrafine WC (WCUF, 0.5 µm) or W (1 µm) and C (0.3 µm) (W+C)UF additives on the densification, microstructure and mechanical properties of coarse-grained cemented carbides were compared systematically. Overall, the cemented carbides with WCUF/(W+C)UF additives are almost fully densification to be higher than 99%, and the average grain size is kept above 2.8 µm. The WCUF additive assists grains to (truncated) trigonal prism shape by two dimensional (2D) growth, whereas the (W+C)UF additive assists grains to rounded shape by three dimensional (3D) growth, lowers WC contiguity and increases face-centered-cubic Co. The hardness and bending strength of (75WCC-15WCUF)-10Co are 86.6 HRA and 2 272 MPa, respectively, both higher than those of (75WCC-15(W+C)UF)-10Co, which could be ascribed to the enhanced densification and unblemished grains. However, the fracture toughness of the (75WCC-15(W+C)UF)-10Co is 23.5 MPa·m1/2, higher than that of the (75WCC-15WCUF)-10Co due to the uniform WC-Co structure and flexible binder phase. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index