采用镶嵌式扩散偶,在不同退火处理条件下,对Ti/Cu扩散溶解层的形成机制进行了研究。利用扫描电子显微镜背散射电子像和二次电子像观察和分析扩散溶解层的形态和结构,从扩散、溶解与结晶角度研究扩散溶解层的形成机制。结果表明:在不同的扩散温度和时间下,Ti/Cu相界面扩散溶解层的形成是Ti和Cu固相扩散、溶解与结晶的结果 相界面处将几乎同时结晶出不同层数、厚度和结构的扩散溶解层 Cu或Ti原子百分含量相对较低的Cu-Ti化合物优先形成,究竟形成一个还是几个相层,这主要由Cu在Ti中和Ti在Cu中的的浓度分布决定。Ti和Cu在700℃固相扩散时,原子扩散流为Cu扩散进入Ti,Ti很少扩散进入Cu,因此,除了Cu4Ti相层在Cu丝上形成以外,其余5个相层都在Ti基体上形成 Cu2Ti和Cu3Ti2以及Cu4Ti3和CuTi化合物相层几乎同时形核并以"竹笋状"方式相向长大,互相交错重叠,表现出比较明显的浮凸 另外,Cu4Ti和CuTi2化合物相层以"平面状"方式长大。
By using diffusion couple made by inlaying, the forming rule of Ti/Cu diffusion-solution zone was researched with different anneal conditions. The microstructure was observed and analysed by means of backscattered electron and secondary electron image. The forming mechanism was researched in the views of diffusion, dissolve and crystalline. The results show that the formation of diffusion-solution zone comes from the solid phase diffusion, dissolve and crystalline of Ti and Cu at different diffusion temperatures for different times. The diffusion-solution zones with different numbers of layer, thickness and structure are formed almost in the Ti/Cu interphase at the same time; the Cu-Ti compound with a relatively lower percent content of Cu and Ti atom is firstly formed; one layer or several layers are formed on earth, which is determined by the concentration distribution of Cu in Ti and Ti in Cu. When the diffusion couple is heated at 700 ~C for 100 h, the atom diffusion flow is the Cu diffusing into Ti, the Ti hardly diffusing into Cu. Consequently, the other five layers are formed on the Ti body except the Cu4Ti layer on the Cu filaments; the Cu2Ti and Cu3Ti2 as well as the Cu4Ti3 and CuTi phase layers grow with the opposite directions and intervein each other with bamboo shoot shape, showing relatively obvious floating and protruding, otherwise, the Cu4Ti and CuTi2 phase layer grows with a "plane pattern".