TC4/QAL10-3-1.5直接扩散连接形貌分析

对TC4/QAL10-3-1.5直接扩散连接的研究表明:在连接温度T=850℃、连接压力P=8 MPa、保温时间t=30 m in的条件下,能够实现接头的扩散连接,然而在扩散接头的局部有裂纹产生。利用扫描电镜对扩散接头进行了显微组织分析,利用能谱仪对扩散接头的元素扩散距离和浓度分布进行了分析。结果表明:形成了厚度为10μm的扩散接头,元素扩散距离与保温时间之间满足抛物线规律x2=Kp(t-t0);由于Cu与Ti的扩散系数不同,导致发生扩散接头向TC4方向偏移的克肯达尔现象。利用界面孔洞理论解释了裂纹产生的机理,提出了工艺改进的方法,并获得了较好的效果。

Pattern analysis on diffusion bonding of TC4 and QAL10-3-1.5

Diffusion bonding of TC4 and QAL10-3-1.5 was carried out under the condition of 850 ℃,8 MPa and 30 min,but there are cracks existing on local area of diffusion zone.Microstructure of diffusion zone was analyzed using scanning electron microscopy(SEM),and diffusion distance and concentration distribution of elements were analyzed using EDS.The result shows that the transition zone thickness is 10 μm.Diffusion distance of element increases with increasing bonding time followed a parabolic law: x~2=K_p(t-t_0),and phenomenon of transition zone moving to TC4 are observed which is so called kirkendall effect.The occurrence of the cracks on the diffusion zone was studied in the theory of interfrcial pore and the reason for micro-cracks produced and improvement methods are found out.Thus,approving diffusion joint is attained by improving the welding process.