Effect of Y2O3 on properties of oxide-bonded Ti(C,N)composites
To investigate the effect of rare earth oxides on the properties of Ti(C,N)composites,oxide-bonded Ti(C,N)materials were prepared by carbothermal reduction nitridation at 1 600 ℃ using TiO2 pow-der,graphite powder and Si powder as raw materials,and Y2O3 powder as sintering aids.The effect of the Y2O3 addition(1％,2％,and 4％,by mass)on the phase composition,microstructure,and physical proper-ties of the Ti(C,N)composites was investigated.The results show that the primary phases in the samples after high-temperature firing are Ti(C,N),Ti3O5,α-quartz,and Y2Si2O7.As the Y2O3 addition increases,there is a corresponding rise in the production of the liquid phase within the specimens,resulting in coarse-ning of Ti(C,N)grains and non-uniform distribution of Y2Si2O7,ultimately leading to a degradation in the mechanical properties of the specimens.When the Y2O3 addition is 1％,the average size of Ti(C,N)grains is approximately 0.76 μm,the composite exhibits high density and excellent mechanical properties,with the apparent porosity of 0.8％,cold modulus of rupture of 242.2 MPa,and elastic modulus of 230.3 GPa.
yttriaTi(C,N)carbothermal reduction nitridationcold modulus of rupturegrain size
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