钛合金表面激光熔化沉积钛基复合材料涂层的组织及性能

Microstructure and Properties of Laser Melting Deposited Titanium Matrix Composite Coating on Titanium Alloy

摘要:

通过激光熔化沉积TA15+30%TiC(体积分数)混合粉末，在TA15钛合金表面制备出钛基复合材料涂层，分析了涂层的组织、硬度及界面结合强度。结果表明，激光熔化沉积过程中原始TiC颗粒发生溶解，并在凝固过程中重新析出细小的TiC，TiC有等轴状及枝晶两种形态，涂层中存在部分未熔的TiC颗粒；涂层硬度达HRC 60；涂层与基体界面为完全冶金结合，涂层的界面结合强度大于310 MPa，抗剪切强度为330 MPa；经弯曲及热震试验后，涂层未出现剥落现象，表明涂层与基体具有很好的相容性

Abstract:

Titanium matrix composite coatings were prepared on TA15 titanium alloy surface through laser melting depositing pre-mixed TA15+30%TiC powders (volume fraction). The microstructure, the hardness and the interface bonding strength of the coating were investigated. The results show that during the laser melting deposition process, original TiC particulates dissolved and re-precipitated fine TiC in the solidification process. The precipitated TiC presented two different morphologies, i.e. equiaxed and dendrite. There were some unmelted TiC particulates in the coating. The hardness of the coating was up to HRC 60. The coating was metallurgical bonded with the substrate. The interface bonding strength was higher than 310 MPa and the shearing strength of the coating were 330 MPa. There was no debonding after bending and thermal shock tests, indicating the good compatibility of the coating with the titanium alloy substrate