Study On The Microstructure And Electrochemical Corrosion Behavior Of TC4 Alloy Prepared By Powder Feeding Laser Additive

Laser additive manufacturing of TC4 titanium alloy(Ti-6Al-4V)has been applied in aerospace and other fields,which is an international research hotspot.Traditional research focused on process optimization,microstructure,friction and wear performance and other directions,but its electrochemical corrosion was rarely reported.In this paper,process optimization experiments were carried out for powder feeding laser additive manufacturing TC4 alloy.Single-layer and multi-layer TC4 alloy cladding layers were prepared on titanium alloy substrates.The microstructure,microhardness,friction and wear behavior of powder feeding laser additive manufacturing TC4 alloy were analyzed,and electrochemical corrosion behavior was studied in 3.5 wt.%NaCl solution and 0.5 mol/L H2SO4 solution.The main work contents are as follows:(1)Different scanning speeds(4?16 mm/s),laser power(1?3 kW)of single-channel single-layer TC4 alloy cladding layers,different scanning speeds(4?16 mm/s)multi-channel single-layer TC4 alloy cladding layers,were all prepared by laser additive manufacturing on titanium alloy plate,multi-channel multi-layer TC4 alloy additive manufacturing experiments at different scanning paths(triangle,rectangle,cross,one-way,oblique 30°)were carried out with optimized parameters.(2)The dilution rate of single-channel single-layer TC4 alloy was analyzed,the microhardness of powder feeding laser additive manufacturing TC4 alloy was tested,and the microstructure,phase and element distribution were analyzed by scanning electron microscopy,XRD diffractometer and EDS spectroscopy.(3)The friction and wear behavior were studied,including the wear mechanism,wear scar and wear debris morphology,and the distribution of element distribution in the wear debris.A three-dimensional model was established by white light interferometer based on the surface profile of cladding layer,in comparison with the substrate,the wear height and width were analyzed.(4)The electrochemical corrosion behavior in 3.5 wt.%NaCl solution and 0.5 mol/L H2SO4 solution was studied,in comparison with the substrate,dynamic potential polarization curve,AC impedance spectroscopy,the corresponding equivalent analog circuit and corrosion mechanism were analyzed.