Cu/Al复合板双辊铸轧复合界面压力分布与结合特性（英文）

双辊铸轧工艺制备双金属层复合板的力学性能和产品厚度规格与结合界面相互作用力学行为密切相关。以铸轧速度为变量，建立热流耦合模拟与界面压力分布计算模型。结果表明，随着铸轧速度的降低，界面温度降低，界面压力与出口铝侧厚度占比增大。铜带减薄主要发生在后滑移区。较高的界面压力和较长的固体/半固体接触时间使结合面充分浸润，为原子扩散提供有利条件。当铸轧速度为2.4 m/min时，扩散层宽度为4.9μm，剥离后铜侧表面被铝覆盖，铝侧发生韧性断裂，有效防止界面分层及裂纹扩展。同时，高界面压力及塑性应变下的剪切作用更显著，铝侧显微组织为细长柱状晶体。因此，结合界面实现冶金结合并细化铝侧晶粒可以使复合板获得较高的结合强度和拉伸性能。

Interfacial pressure distribution and bonding characteristics in twin-roll casting of Cu/Al clad strip

The mechanical properties and product thickness specifications of bimetallic clad strip prepared by twin-roll casting are tightly related to the mechanical behavior of bonding interface interaction. The thermal?flow coupled simulation and the interface pressure calculation models are established with the cast-rolling velocity as the variable. The results show that the interface temperature decreases, the interface pressure and the proportion of the thickness of the Al side increase with the decrease in cast-rolling velocity. The thinning of Cu strip mainly occurs in the backward slip zone. The higher pressure and longer solid/semi-solid contact time make the interface bonded fully, which provides favorable conditions for atomic diffusion. The inter-diffusion zone with a width of 4.9 μm is attained at a cast-rolling velocity of 2.4 m/min, and the Cu side surface is nearly completely covered by aluminum. Therefore, the ductile fracture occurs on the Al side, which prevents the propagation of interface delamination cracks effectively. Meanwhile, shear effect becomes more significant at high interfacial pressure and large plastic strain, and the microstructure on Al side is composed of slender columnar crystals. Thus, the metallurgical bonding and refinement of grains on the Al side can result in higher bonding strength and tensile properties of the clad strip.