冷轧对铸轧钛铝复合板界面组织与性能的影响

Effect of Cold Rolling on Interfacial Microstructure and Properties of Ti-Al Roll-casted Composite Plate

采用铸轧法制备钛铝复合板并对其进行冷轧处理,使用万能试验机对不同变形量的复合板进行力学性能检测,用显微硬度计测量界面层附近的显微硬度,通过光学显微镜及扫描电子显微镜观察其界面结合情况、微观组织及拉伸断口形貌。研究结果表明:随着压下率的增加,界面层两侧的硬度逐渐增大。当压下率为23%时,复合板的抗拉强度从铸轧态的172 MPa增加到215 MPa,延伸率从34%下降到16%,界面层仅有少量裂纹。随着压下率的增加,抗拉强度缓慢增加,界面处裂纹的长度和宽度迅速增加,界面层迅速减薄。当压下率达到53%时,界面层破损严重,钛铝两种金属的主要结合方式由冶金结合变为机械啮合。

The Ti-Al composite plate was prepared by cast-rolling method and cold rolling. Mechanical properties of different deformations of composite plate were detected by universal testing machine. The microhardness near the interface layer was measured by the microhardness tester. The microstructure,tensile fracture morphology and interface combination were observed by the optical microscope and scanning electron microscope( SEM). The results show that the micro hardness of both sides of the interface layer improves gradually with the increase of reduction ratio. When the reduction ratio is 23%,the tensile strength of the composite plate increases from 172 MPa to 215 MPa,but the elongation decreases from 34% to 16%,meanwhile the interfacial layer only has a little crack. With the increase of reduction ratio,the tensile strength increases slowly,but the cracks length and width of the interfacial layer increase rapidly and the interfacial layer becomes thinner rapidly. When the reduction ratio is 53%,the interfacial layer is damaged seriously,and the main combination of Ti and Al changes from the metallurgical bonding into the mechanical engagement.