Ni_3Al粘结相对Ti(C,N)基金属陶瓷组织性能的影响

采用粉末冶金法制备了Ni3Al做粘结相的Ti(C,N)基金属陶瓷,研究了添加不同含量Ni3Al粘结相的金属陶瓷的力学性能和显微组织并与Ni做粘结相的金属陶瓷进行了对比。结果表明,Ni3Al作粘结相的金属陶瓷综合力学性能总体上不如Ni做粘结相的金属陶瓷,随着金属陶瓷中Ni3Al含量的增加,其洛氏硬度值不断下降,而抗弯强度和断裂韧性却不断增加;显微组织分析表明,Ni3Al做粘结相的金属陶瓷同样具有芯环结构,Ni3Al可以控制环形相的厚度,抑制晶粒异常长大,使硬质相芯相棱角圆润。Ni3Al含量为30wt%左右的金属陶瓷能够兼顾硬度和抗弯强度等力学性能,此时的主要力学性能指标为:抗弯强度1 045±80 MPa,洛氏硬度HRA89.7±0.25,断裂韧性KIC为14.26 MPa·m1/2。

Effect of Ni3AI Binder on Microstructure and Properties of Ti（C,N）-based Cermets

Ti（C,N） based cermets using Ni3Al as binder phase were prepared by powder metallurgy method. The effect of different content of Ni3AI addition on microstructure and mechanical properties of the cermets was studied and it was also compared with cermets with Ni binder. Results show that the comprehensive mechanical properties of cermets with Ni binder are better than that of cermets with Ni3Al binder. With the content of Ni3Al increasing, the Rockwell hardness continuously declines while transverse rupture strength and fracture toughness continue to increase. Microstructure analysis shows that cermets with Ni3A1 binder have the same typical core/rim structure. Ni3Al can control the thickness of rim phase, inhibit abnormal grain growth and make the hard core phase having rounded edges and corners. The mechanical properties of samples with the content of 30%Ni3AI （mass fraction） are obtained as 1 045±80 MPa for TRS, HRA 89.7±0.25 for hardness and 14.26 MPa.m1/2 for KIc, respectively.