Achieving superior burn resistant and mechanical properties of Ti40 alloy by laser solid forming

Abstract

Laser solid forming (LSF) technology had a great influence on the manufacturing of aeronautical burn resistant titanium alloy Ti40, which was related to the comparison and competition between additive manufacturing and traditional forging parts. The Ti40 deposition blocks were fabricated using the LSF technique and tested for microstructure, mechanical properties and burn resistance. The results showed that, compared with the forged sample, the grain of LSFed sample was refined to a certain extent, and α phase and Ti5Si3 phase were precipitated. The tensile and yield strengths of the LSFed Ti40 alloy were 965 MPa and 962 MPa, respectively, which were higher than those of the forgings, and the elongation was close to that of the forgings. The fracture mechanism was a mixture of ductile and brittle fractures. The area and depth of the ablation pit and the area of the thermal zone of influence in the LSFed sample were smaller than in the bifurcated state. The Ti5Si3 precipitated in the LSFed sample not only improved the oxidation efficiency of the V and Cr elements by retaining the pores, but also slowed down the spallation of the oxide layer by strengthening the binding of the matrix to the oxide layer and improved the burn resistance of Ti40. Overall, the tensile strength and elongation of the LSFed Ti40 alloy were up to the forging standard, and the burn resistance was better than that of the forged Ti40 alloys.