Microstructure and mechanical properties of Ti-6Al-4V components fabricated by laser micro cladding deposition

Laser micro cladding deposition manufacturing (LμCDM) is a newly developed rapid manufacturing method for metals. The LμCDM technology adopts a novel powder feeding method based on alternating friction and inertia force, and this powder feeding method can effectively improve the accuracy and orientation of the powder injection, resulting in a smaller molten pool size and a higher cooling rate of liquid metal. Therefore, the components fabricated by LμCDM could obtain the finer microstructures and the improved mechanical properties. It is found that the components fabricated by LμCDM are fully dense free of cracks or pores and exhibit columnar prior β grains with a finer acicular α′ phase microstructure. The microhardness (HV_0.2) of the thin-wall component is HV 400–HV 500 in the majority part of the cross section and can reach about HV 850 in the top region. The ultimate tensile strength (UTS) and elongation show insignificant dependence on the testing directions of the tensile specimens. The UTS is between 1,002 and 1,100 MPa, and the elongation is between 10.0 % and 14.7 %.