The microstructure and mechanical properties of a titanium alloy and steel with a bimetallic interlayer by hot isostatic pressure diffusion bonding

Hot isostatic pressing (HIP) is an effective forming method for producing bimetal parts in steel and titanium alloys with large contact areas and complex joining surfaces. In this study, a Cu/Nb bimetallic layer was employed as an intermediate layer to prevent the formation of intermetallic compounds at the steel–titanium alloy interface. The influence of HIP temperature on the microstructure, phases, elemental distribution and shear properties of the DT300/Cu/Nb/TC11 interface was investigated, and the deformation behaviour of the composite samples was elucidated through finite-element simulation. The results showed that as the HIP temperature increased from 900°C to 1000°C, the number of pore defects at the interface decreased, and the composite's shear strength increased from 171 to 215 MPa. The finite element simulation of the composite sample's shear deformation indicated that the properties of the Cu layer primarily influenced the composite sample's mechanical behaviour.