Research On Laser Deposition Repair TA15 Titanium Alloy Technology

Laser Deposition Manufacturing(LDM)is a new type of material forming and manufacturing process.It successfully solves the problems of titanium alloy processing,such as difficulty of forming and material wasting.It has become an important processing method for titanium alloys.However,in the process of laser deposition manufacturing and service,parts may cause defects and cause economic losses.Laser Deposition Repairing(LDR)is a new repairing process that combines the advantages of both laser cladding and laser stereoforming.It can effectively solve the drawbacks of traditional repair methods and solve the quality problems caused by parts in production and use.In this paper,laser damage repair technology(LDR)was used to repair the internal damage of LDMed TA15.Firstly,the microstructure was observed.It was found that the whole microstructure of the sample after repair was the basket structure,which was the same as the tissue type before the repair,but the heat treatment system of the base material area and the repair area was different.The microstructure of the base material area is coarser than that of the repair area,and the heat affected zone between the two areas gradually transitions from coarser to fine.Then,the tensile properties of the laser deposition repair samples were studied.It was found that the tensile specimens after repair were broken at the base material with relatively poor strength,so the tensile strength did not change much compared with the original sample.It can be found that the fracture modes are ductile mode.The tensile properties of the repaired specimens can be compared and analyzed by different angle sampling methods.It can be found that the inter-clamping between the ?-columnar direction and the tensile stress direction has a great influence on the performance.Finally,the fatigue properties of the repaired samples were studied.The fatigue strength of the repaired samples is 542 MPa,which is slightly lower than that of the laser deposition manufactured samples,i.e.,555 MPa.However,when the stress level is high,the small size of the microstructure in repaired samplesis prominent,and the fatigue life is higher than that of the laser deposited samples.The repaired part has strong microstructure sensitivity,and all the fatigue crack source from the pore.The crack initiation region was characterized by obvious?,? lamellar tearing and crystallographic cleavage facets of them.At the stage of crack propagation,often accompanied by secondary cracks.Increase energy consumption and improve fatigue strength.