Effects of CMT+P process and post heat treatment on microstructure and properties of TC4 component by additive manufacturing

CMT + P procedure was used in wire and arc additive manufacturing of TC4 titanium alloy. Aiming at inhomogeneity in microstructure and properties by heat accumulation in addictive manufacturing process, two heat treatment processes were used to improve the inhomogeneity and promote the performance of component by addictive manufacturing. The results showed that the as-built wall in a good appearance can be obtained with CMT+P procedure. When the wire feeding speed is 6 m/min and the welding torch speed is 0.3 m/min, the heat input is 313 J/mm, and the microstructure of as-built wall is continuously growing from bottom to top. The grain size for different positions of sample becomes uniform and the resistance to plastic deformation for the sample is enhanced after heat treatment. Tensile testing shows that the component has the highest tensile strength of 1 124 MPa under 600℃ and 4 h condition. The fracture analysis shows that all the fracture modes are ductile fracture.