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

Bo Yao^1,2,3,4，Xu-Long Ma^1,2,3，Feng Lin^1,2,3，Wen-Jun Ge^1,2,3

1. Key Laboratory for Advanced Materials Processing Technology,Ministry of Education of China2. Key Laboratory for Biomanufacturing and Rapid Forming Technology3. Department of Mechanical Engineering, Tsinghua University4. Department of Mechanical Engineering, Army Aviation Institute of Chinese People’s Liberation Army

摘 要：Laser micro cladding deposition manufacturing（Ll CDM） is a newly developed rapid manufacturing method for metals.The Ll CDM 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 Ll CDM could obtain the finer microstructures and the improved mechanical properties.It is found that the components fabricated by Ll CDM are fully dense free of cracks or pores and exhibit columnar prior b grains with a finer acicular a0 phase microstructure.The microhardness（HV0.2） 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 tensilespecimens.The UTS is between 1,002 and 1,100 MPa, and the elongation is between 10.0 % and 14.7 %.

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