TiC-TiB_2陶瓷与Ti6Al4V熔化连接及层状复合材料制备

Layered composite of solidified TiC-TiB_2 ceramic to Ti-6Al4V alloy achieved by fusion bonding

通过引入Ti-6Al-4V合金板,采用超重力场燃烧合成技术,在制备细晶TiC-TiB2凝固陶瓷的同时,实现了陶瓷-钛合金的熔化扩散焊,进而制备出具有成分梯度特征的陶瓷-钛合金层状复合材料.陶瓷-钛合金层间接头组织表明,正是因超重力场燃烧合成的爆燃特性及超重力场对燃烧产物形成的高温真空环境,使得钛合金表面发生熔化,进而发生液态陶瓷-钛合金液相层间的原子互扩散现象,故在陶瓷-钛合金连接区形成钛合金与富钛碳化物呈相间分布且细小TiB2片晶镶嵌其上的凝固组织,并使陶瓷-钛合金接头呈现成分梯度特征,进而使得陶瓷-钛合金的连接抗剪强度达到450 MPa±35 MPa,层状复合材料硬度从陶瓷至钛合金一侧则呈线性逐渐减小.

By introduction of Ti-6Al-4V plate at the bottom of combustion system in high-gravity field,fusion bonding of TiC-TiB2 ceramic to Ti-6Al-4V alloy was achieved.The solidified TiC-TiB2 ceramic with fine grains was prepared by combustion synthesis.Furthermore,the ceramic to titanium layered composite with chemical composition gradient was obtained.The microstructure of fusion bonding of TiC-TiB2 ceramic to Ti-6Al4V alloy indicates that,the presence of chemical reaction in explosive combustion and the subsequent thermal vacuum induced by liquid products in high-gravity field make Ti alloy partially fused.Then atomic inter-diffusion occurs spontaneously between liquid ceramic and molten Ti alloy,resulting in the achievement of the joint.Microstructure analysis shows that in the bonding joint,titanium riched carbides are distributed homogeneously with fine TiB2 grains embedded in the matrix of Ti alloy.Shear strength of 450 MPa ± 35 MPa is achieved between the ceramic and Ti alloy.Vickers hardness decreases linearly from the ceramic to Ti alloy.