The Preparation And Research On The Microstructure&Properties Of Ti（C,N）-Ni/Ni₃Al Cermets

Ti(C,N)-based cermets were normally prepared with Ni or Ni/Co as binder, which haveextensive application prospect in the field of advanced tools and dies due to their highhardness, excellent wear resistance, superior adhesion resistance etc. Ni3Al intermetalliccompound has been widely utilized due to its high melting point, low density, goodresistance to oxidation and corrosion, high thermal conductivity, and its outstandingmechanical properties at high temperature. Therefore, It is of great importance to study theaddition of Ni3Al as binding phase. In this paper, Ti(C,N)-Ni/Ni3A1composite materialwere prepared and the structures and properties were investigated.In this study, Ni3Al prealloy powder and Ni、A1powder were added to prepareTi(C,N)-Ni3A1composite materials and the microstructure and properties of these twocomposite materials were compared and analysed; Further research about the influence ofthe sintering temperature and C/N ratio on the microstructure and properties of Ti(C,N)-Ni/Ni3A1cermets prepared by changing the binding phase components were studied.Ti(C,N)-Ni3A1cermets prepared by two different raw powder showed typical core-rimstructure and the formation mechanism related to dissolving-precipitation mechanism. Theresults show that Ti(C,N)-Ni3A1synthesized by using in-situ method with Ni、Al andTi(C,N) powder exhibits higher density, thicker rim structure and better mechanicalproperties, compared with the cermets prepared by Ni3Al prealloy powder.With the increase of sintering temperature the TRS and Rockwell hardness of theTi(C,N)-Ni/Ni3A1goes up firstly and then decrease, TRS can be up to1906.6MPa whileRockwell hardness is89.1HRA when sintered at1450℃. The particle size and rim structurehave been strongly affected by the C/N ratio of Ti(C,N). The particle size and rim thicknessdecreases as the C/N ratio decreases in Ti(C,N)-Ni/Ni3A1. When x was0.5, the cermetsexhibited a smallest particle size and thinnest rim thickness. With the decrease of C/N ratiothe TRS and Rockwell hardness of the Ti(C,N)-Ni/Ni3A1goes up firstly and then decrease,when x was0.3, the cermets showed excellent properties whose TRS and Rockwellhardness was1906.6MPa and89.1HRA respectively.