Effect of Heating Temperature on Microstructure and Mechanical Properties of Q235/Ti Composites Plates with Ni Interlayer

In this paper,a comparative experiment was carried out to prepare titanium/steel rolled composite plates under different heating temperature conditions with Ni as intermediate layer.Scanning electron microscope,energy spectrometer,X-ray diffractometer and Instron universal tensile testing machines and other analytical methods were used to study the effects of heating temperature on the mechanical properties and microstructure of the composite sheets.The results show that when the heating temperature is 850～900 ℃,the shear strength of resulted composite plate increases with the increase of temperature,when the heating temperature is 900～950 ℃,the shear strength decreases with the increase of temperature.The highest shear strength is obtained at 900 ℃.When Ni is used as the intermediate layer,elements such as Fe and C can be effectively prevented from diffusing to the Ti side to form an intermetallic compound,the type of the interface compound does not change with temperature but the number of interfacial compound increases with increasing temperature.When the rolling temperature is 850 ℃,there are very few intermetallic compounds at the interface,and the corresponding shear strength is the lowest.When the rolling temperature is 900 ℃,the interfacial shear strength of the composite plate is the best,and the corresponding interface structure is more sufficient,the element diffusion and a small amount of intermetallic compounds.When the rolling temperature is 950 ℃,the intermetallic compound layer sharply thickens,TiNi₃ and pores increase sharply,thus seriously weakening the shear strength of the interface.