Research on Microstructure and Properties of Laser Cladded TF550 Burn Resistant Titanium Alloy
The effect of process parameters on the forming quality of laser cladded TF550 burn resistant titanium alloy and the evolution of microstructure and mechanical properties were studied.The results show that the influencing factors on sample forming are laser power>scanning speed>powder feeding rate.The top and bottom of the laser cladded TF550 titanium alloy block samples at different laser power are composed of equiaxial prior-β grains,and the middle region is a coarse columnar prior-β grains.With the increase of laser power,the grain size of each region also increases.The microstructure of laser cladded TF550 titanium alloy samples is mainly composed of chicken claw shape TiC phase,point-like Ti5Si3 and acicular α.The average microhardness of the laser cladded TF550 samples shows a pattern of deposition zone>heat affected zone>substrate.The horizontal tensile strength and yield strength of the laser cladded TF550 samples are slightly higher than that of the forgings,but the elongation is only 72%of that of the forgings,and the fracture morphology shows the characteristics of mixed fracture.