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以AMS 4777粉末为填料,研究瞬时液相连接IN-738LC高温合金的显微组织演变,获得完全等温凝固时间。研究间隙大小和连接时间对接头组织的影响。当间隙大小为40μm时,完全等温凝固时间为45 min。在不完全等温凝固的情况下,连接区的残余液相在非平衡条件下冷却,形成γ-γ共晶相。间隙大小与时间存在非线性关系。随着间隙增大,共晶相变宽。在扩散影响区,发现大量合金元素,其浓度达到峰值,这是由于形成了硼化物和硅化物等金属间化合物。随着间隙增加,所需连接时间增加,合金元素有更多的时间进行扩散和分布至更大区域。因此,合金元素浓度随间隙增加缓慢降低。已有双相模型不能准确预测IN-738LC-AMS 4777-IN738LC瞬时液相连接系统的完全等温凝固时间。
AMS 4777 powder was used as a filler to study the microstructure evolution of transient liquid phase connection IN-738LC superalloy, obtaining complete isothermal solidification time. The effect of gap size and connection time on the linker tissue was investigated. When the gap size is 40μm, the complete isothermal solidification time is 45 min. In the case of incomplete isothermal solidification, the residual liquid phase in the connection zone cools under unbalanced conditions to form a γ-γ eutectic phase. Gap size and time there is a nonlinear relationship. As the gap increases, the eutectic phase becomes wider. In the area of influence of diffusion, a large amount of alloying elements are found, and their concentration reaches a peak, which is due to the formation of intermetallic compounds such as boride and silicide. As the gap increases, the required connection time increases and the alloying elements have more time to diffuse and distribute to a larger area. Therefore, the alloying element concentration slowly decreases with increasing gap. Existing biphasic models do not accurately predict the complete isothermal solidification time of the IN-738LC-AMS 4777-IN738LC transient liquid phase connection system.