Evolution of Phase Microstructure and Properties of Mulit-core Cermets Based on (Ti,W,Ta)CN and TiCN Powders in Sintering Process.

The phase, microstructure and properties of multi-core cermets based on (Ti,W,Ta)CN and TiCN powders were investigated in sintering process. The analyses of X-ray diffraction (XRD) and scanning electron microscope (SEM) indicate that the sintering behavior of the multi-core cermet in sintering process could be divided into three stages: (I) pre-densification stage (the sintering temperature < 1200 °C); (II) rapid densification stage (the sintering temperature between 1200 °C and 1350 °C); (III) final densification stage (the sintering temperature > 1350 °C). Meanwhile, the evolution of η -phase in multi-core cermets was discussed as well. Furthermore, the microstructural and chemical composition of η -phase were studied by transmission electron microscopy (TEM) using X-ray energy dispersive spectrometry (XEDS) and selected area electron diffraction (SAED). The thickness of the rim structure would increase with the rise of sintering temperature, while the mechanical properties of the material would firstly increase and then decrease with the rise of sintering temperature. The highest transverse rupture strength is achieved at 1450 °C, while the highest hardness at 1390 °C. [ABSTRACT FROM AUTHOR]