Preparation And Microstructure Of TC4/CU Dual Phase Coating By Laser Melting Deposition

Titanium alloy has excellent corrosion resistance,but expensive.Steel is a kind of low price,is the longest see the structure of the material,but poor corrosion resistance.Then the surface of steel to prepare titanium alloy coating or two kinds of materials are welded together,which can not only reduce the cost of parts,but also expanded the application of titanium alloy corrosion in industry.The traditional solid phase welding?melt welding to connect the titanium alloy and steel,but that can not avoid to produce brittle intermetallic compound between TC4/Fe interface,leading to the corrosion resistance of coating spalling.Thus,it's application value is limited.Laser melting deposition technology can prepare fine microstructures and density,low dilution rate,and base material is metallurgical combination,with Cu alloy as transition layer,why can be a solid solution with Fe matrix in any case,the appropriate process parameters for preparation of Cu based transition layer and prepare TC4 corrosion the coating,transition layer successfully hinder the diffusion of Ti atoms to the Cu/Fe interface and the formation of brittle material.The use of A3 steel as base material,copper alloy as transition layer,TC4 as coating by laser melting deposition technique for the preparation of TC4/Cu duplex coating,this paper mainly studies the influence of process parameters on the microstructure and properties of TC4/Cu duplex coating,and compared with commercial TC4 titanium alloy,TC4/Fe coating,A3 steel,the main results are as follows:IPG fiber laser spot diameter 4mm in A3 steel on the preparation of Cu based transition layer in the laser power 1400W,scanning speed is 10mm/s,lap width is the best quality 2mm coating;TC4 coating was prepared on Cu based on the transition layer,in 1800W laser power,scanning speed is 10mm/s,lap width for the best quality 2mm coating.TC4/Cu duplex coating each interface between the diffusion of atoms,and alpha-Fe,-Ti solid solution to achieve metallurgical bonding interface is formed at the interface,and the microstructure of the transition layer in the middle;Ti-Cu-Fe,three yuan in the laser melting solidification microstructure,and deposition of TC4 coating in CuTi2 a small amount of metal compounds.There are intermetallic compounds such as FeTi and Fe2Ti at the TC4/Fe interface,and there are cracks at the interface.The average microhardness of TC4/Cu dual phase coating is 500HV,which is higher than that of commercial TC4 titanium alloy,TC4/Fe coating and A3 steel,and the corrosion resistance of TC4/Cu dual phase coating is the strongest,higher than that of commercial TC4 titanium alloy and TC4/Fe coating,but far higher than that of A3 steel.The TC4/Cu duplex coating only has surface corrosion.The commercial TC4 titanium alloy is mainly intergranular corrosion,while the TC4/Fe coating and A3 steel matrix are mainly pitting corrosion.