将Ti合金插层引入(Ti+B4C)反应原料和Ti合金底板之间,研究Ti合金插层厚度变化对超重力反应连接TiB2基陶瓷/Ti-6Al-4V梯度复合材料界面显微组织与力学性能的影响。热力学计算表明:合成反应的绝热温度远超Ti合金的熔点,可以保证不同厚度的Ti合金插层全部熔化。XRD、FESEM及EDS分析结果表明:在陶瓷和Ti合金底板之间形成梯度界面区,且随着Ti合金插层厚度的增加,梯度界面区的厚度也不断增大。自陶瓷基体至Ti合金底板,TiB2和TiC1-x的体积分数不断减少,而TiB的体积分数先增加而后减少,最终形成以TiB2、TiC1-x及TiB陶瓷相尺寸和分布为特征的梯度复合结构。而梯度连接区的硬度分布趋势更加平缓,其剪切强度不断提升。
By introducing Ti alloy interlayer between(Ti+B4C)reactant and Ti alloy substrate,the effect of thickness variations of Ti alloy interlayer on the microstructure and mechanical properties of the interface of TiB2 based ceramic/Ti-6Al-4Vgraded composites has been discussed,which were prepared by reaction bonding in high gravity field.The thermodynamic calculation shows that the adiabatic temperature of synthesis reaction is much higher than the melting point of Ti alloy,which ensures Ti alloy interlayer with different thickness completely melts.The XRD,FESEM and EDS analysis results show that the graded interface zone between ceramic and Ti alloy substrate forms,and the thickness of which increases with increasing thickness of Ti alloy interlayer.The volume fraction of TiB2 phase and TiC1-xgradually reduces,but the volume fraction of TiB first increases and then decreases from ceramic matrix to Ti alloy substrate,finally,on which there is the presence of the graded composite structures characterized by the size and distribution of TiB2,TiC1-xand TiB ceramic phases.And hardness distribution trend of the gradient connection area becomes smooth and shear strength improves gradually.