(TiB_2-TiC)_pNi/TiAl/Ti梯度材料的制备及性能分析

Preparation and Property Analysis of(TiB_2-TiC)_p Ni/TiAl/Ti Functionally Gradient Materials

采用电场激活压力辅助燃烧合成技术(FAPAS)制备了功能梯度材料(TiB2-Ti )pNi/TiAl/Ti。界面微观分析表明:Ti粉和B4C粉原位合成了(TiB2-TiC)pNi复合陶瓷,Ti粉和Al粉反应生成了中间层TiAl,TiAl与其两侧的复合陶瓷和钛板均实现了良好连接;(TiB2-TiC)pNi复合陶瓷晶粒细小均匀,TiB2和TiC颗粒均匀地分布在Ni基体中。剪切实验表明:试样的剪切强度随施加电流和压力的增大而增大,剪切强度最大达到了85.78 MPa。对断裂界面的SEM分析表明,断裂裂纹发生在(TiC-TiB2)pNi复合陶瓷与TiAl的连接界面处。通过FAPAS方法合成梯度材料过程中,高温下增大电流可以有效促进界面间的扩散,从而提高界面的连接强度,而压力能够细化复合陶瓷的晶粒,使晶粒变细,对梯度材料强度提高也有一定的促进作用。

The（TiB2-TiC）p Ni/TiAl/Ti functionally gradient materials（FGMs） have been prepared by Field-Activated PressureAssisted Synthesis（FAPAS） processes.Interface microanalysis shows that（TiB2-TiC）p Ni composite ceramic is prepared by in-situ synthesis with Ti and B4 C powders,the interlayer TiAl produced by reaction of Ti and Al powders has a good bonding with the composite ceramic and titanium plate on both sides,and（TiB2-TiC）p composite ceramic particles are fine and even,with TiB2 and TiC particles homogeneously dispersing in Ni matrix.Shear tests show that the shear strength of samples increases with the applied current and pressure,with the maximum of 85.78 MPa.SEM analysis of the fracture shows that the fractures occur in the（TiC-TiB2）p Ni/TiAl interface.In the preparation of FGMs by FAPAS,increasing current under high temperature will effectively promote the dispersion and bonding strength in the interface,and the pressure will fine the particles of composite ceramic to give some improvement on the strength of FGMs.