Microstructure And Property Research Of Laser Additive Repair TA15/TC17 Alloy

TC17 titanium alloy is mainly used in the manufacture of engine integrally bladed disk,turbofan and so on.It is easy to occur edge ablation,wear damage in the course of service.For the integrally bladed disk,the integrally bladed disk may be destroyed because of the damage of one blade.Laser additive repair technology has the advantages of small heat input,near net forming and so on.It can meet the requirements of rapid and high quality repair of parts and components.At present,the research mainly focuses on the laser repair of titanium alloy with homogeneous materials.When using homogeneous materials,the hardness of the repair zone is slightly higher than that of the wrought substrate,and the mechanical properties can not match the wrought substrate completely.Choosing the heterogeneous powder material with low hardness is beneficial to match the hardness of the substrate with the repair area.First,the influence of process parameters on the single channel characteristic size of TA15/TC17 laser additive repair was studied by optimizing the process parameters.The microstructure of defects such as no porosity and poor fusion was obtained,and the combination of low power process parameters was obtained.Secondly,the influence of technological parameters on the characteristic size of molten pool,the relationship between microstructure and mechanical properties of laser additive repair TA15/TC17 were studied.The average tensile strength of the deposited samples is 1029 Mpa,which is up to 90.2% of that of TC17 titanium alloy wrought substrate,which is 10.6%higher than that of TA15 titanium alloy wrought substrate.Finally,in order to improve the mechanical properties and meet the requirements of service,the effects of different annealing temperatures and annealing methods on the microstructure,tensile properties and microhardness of TA15/TC17 laser additive repair were studied.The results show that when the annealing temperature is 650 C,the tensile strength of1102 Mpa,increases by 7.1% compared with the deposited samples,and reaches 98.4% of that of TC17 titanium alloy wrought substrate.The elongation is 13.5%,which is obviously higher than that of deposited samples,and higher than that of TC17 titanium alloy and TA15 titanium alloy wrought substrate.