Effect of sintering atmosphere on microstructure and properties of TiC based cermets

Abstract

The effect of the sintering atmospheres (vacuum, N 2 , Ar) on the microstructures and properties of the TiC based cermets was studied using XRD, SEM/BSE and energy dispersive spectrometer. Compared with the alloy sintered in vacuum, the carbon content of the specimen sintered in N 2 and Ar is lower by 0.5%; and the nitrogen content is higher by 0.3% when sintered in nitrogen. The central part of the ring structure may be carbide with either a high W or Ti content. The ring structures are (Ti, W, Ta, Mo, Co, Ni)C solid solutions with different metallic elements and distributions. The composition of the binder phase is (Co, Ni) solid solution with different Ti, W, Ta, Mo, C contents. The structures are uniform for the cermets sintered in vacuum and the properties are the best. When sintered in Ar or N 2 , the O 2 and N 2 in the atmosphere take part in the sintering reaction to break the carbon balance in the cermets to form a shell structure and defects, which results in poor density, microhardness (HV) and transverse rupture strength (TRS).

Microstructure and Properties of TiC Steel-Bonded Carbide Used Fe/Mo Pre-Alloyed Powder as Binder

“…In order to improve the wettability of TiC phase and binder phase, Molybdenum is an necessary metal used effectively. Molybdenum is used commonly in the research and production of cemented carbide, steel-bonded carbide, metal/ceramic composite material [8][9][10][11][12][13][14][15][16][17][18]. Particularly when the alloy contains TiC or Ti(C,N) hard phase, molybdenum is an essential metal in the metallic binder.…”

Preparation of Ni–Mo–C/Ti(C,N) coated powders and its influence on the microstructure and mechanical properties of Ti(C,N)-based cermets

“…Molybdenum is a very important component of Ti(C,N)-based materials and is generally added as a raw powder of Mo 2 C. With the addition of Mo 2 C, the wettability of the Ni binder to Ti(C,N) grains can be improved and the ceramic grains can be refined. In previous studies, great progresses of Ti(C,N) based cermets have been achieved around the design and optimization of alloy composition, preparation technology, microstructure and cutting performance [3][4][5]. As one kind of composite materials, Ti (C,N)-based cermets consist of many different raw material powders, which leads to a complex microstructure.…”