Microstructure evolution, mechanical properties and tailoring of coefficient of thermal expansion for Cu/Mo/Cu clad sheets fabricated by hot rolling

Abstract

The law of microstructure evolution and mechanical properties of hot roll bonded Cu/Mo/Cu clad sheets were systematically investigated and the theoretical prediction model of the coefficient of thermal expansion (CTE) of Cu/Mo/Cu clad sheets was established successfully. The results show that the deformation of Cu and Mo layers was gradually coherent with an increase in rolling reduction and temperature and excellent interface bonding was achieved under the condition of a large rolling reduction. The development of the microstructure and texture through the thickness of Cu and Mo layers was inhomogeneous. This phenomenon can be attributed to the friction between the roller and sheet surface and the uncoordinated deformation between Cu and Mo. The tensile strength of the clad sheets increased with increasing rolling reduction and the elongation was gradually decreased. The CTE of Cu/Mo/Cu clad sheets was related to the volume fraction of Mo. The finite element method can simulate the deformation and stress distribution during the thermal expansion process. The simulation result indicates that the terminal face of the clad sheets was sunken inward.