轧制复合制备TA1/AZ31B/TA1层状复合材料组织与性能研究

Study on microstructure and properties of TA1/AZ31B/TA1 laminated composites produced by roll bonding

本文通过轧制复合法制备了TA1/AZ31B/TA1层状复合材料,利用光学显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)和电液压伺服疲劳试验机等测试方法分析研究了复合材料的界面、显微组织、应力-应变曲线及拉伸断口形貌。结果表明:轧制复合后,其结合界面呈波浪状,且在TA1层次表面有裂纹出现;经5道次轧制后,AZ31B挤入裂缝中,TA1侧表面层镶嵌在AZ31B基体中,并发生断裂并破碎,界面结合具有机械啮合特性。在轧制复合首道次后,TA1层组织变化不明显,AZ31B层组织明显细化,分布极不均,且发生了动态回复与再结晶;轧制5道次后,TA1层组织沿轧制方向呈流线型纤维组织,AZ31B层组织呈细小的等轴晶,分布均匀;当拉伸速率为1mm/min时,TA1/AZ31B/TA1层状复合材料抗拉强度达到最大值359.469 MPa,比准静态(0.01mm/min)增加了30 MPa,提高了9.09%,但延伸率降低了8.471%,表明TA1/AZ31B/TA1层状复合材料是一种正应变速率敏感材料。

In the present studying, the interface, microstructure, and properties of TA1/AZ31 B/TA1 laminated composite produced by roll bonding and investigated by optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and electrohydraulic servo fatigue testing machine. The results showed that the shape of bonding interface structure was wavy after the first roll bonding, and there were a few cracks on the subsurface of TA1 side. After 5 passes of rolling, AZ31 B was pushed into the crack, and the surface layer of TA1 side was embedded in AZ31 B matrix, and then was fractured. So the bonding interface has mechanical meshing characteristics. After the first roll bonding, the microstructure of TA1 layer had little changed, while that of AZ31 B layer was obviously refined with the extremely inhomogeneous distribution, and occurred dynamic recovery and recrystallization at the same time. After 5 passes of rolling, the microstructure of TA1 layer was streamlined along the rolling direction, and the microstructure of AZ31 B layer was fine equiaxed crystal with uniform distribution. When the tensile rate was 1.0 mm/min, the tensile strength of TA1/AZ31 B/TA1 laminated composite reached a maximum value of 359.469 MPa, which was 30 MPa higher than that of the quasi-static(0.01 mm/min) and increased by 9.09%, while the elongation decreased by 8.471%. The results show that TA1/AZ31 B/TA1 laminated composite is a positive strain rate sensitive material.