Microstructure evolution and mechanical properties of the Ti/Ni multilayer composite produced by accumulative roll bonding

Abstract:

In this paper, Ti/Ni composites material with Multi-layered structure was produced by accumulative roll bonding (ARB) process. The micro-structure and interface structure of composites material were analyzed by scanning electron microscope, energySdisperseSspectroscopy, and transmissionSelectronSmicroscope. The mechanical propertiesSof composite material in different ARB cycles were tested by universal material testing machine and micro-hardness tester. The results show that the micro-structure of Ti layer and Ni layer of composites material was obviously refined. Ultrafine grains with the size of 200 um ~ 300 um is acquired in both Ti and Ni layer. And the micro-structureShomogeneity, the tensile strength, micro-harded and interfacial bonding strength were improved with the increasing of ARB cycles. After ARB 5 cycles, the tensile strength was 810 MPa, the elongation was 24.4%, and the average micro-hardness of Ti layer and Ni Layer is 233 HV and 229 HV. There is no obvious diffusion at the interface of Ti/Ni composites material with multi-layered structure during ARB 1-5 cycles.

Key words:accumulative roll bonding(ARB); Ti/Ni multi-layered composite material; micro-structure; mechanical properties