激光粉末床熔融成形TA15合金薄壁结构拉伸性能研究OA

Laser powder bed melting(LPBF)technology offers significant advantages in manufacturing complex thin-walled components and has broad application prospects in fields such as aerospace and biomedicine.In this study,TA15 alloy thin-walled structures with thicknesses ranging from 1 mm to 4 mm were fabricated using LPBF technology.The effects of building thickness on the microstructure,as well as the room-temperature and high-temperature(500 ℃)tensile properties were comprehensively evaluated.The results indicate that as the building thickness increases,the grain size of the primary β phase decreases,while the width of the α laths slightly increases.The ultimate tensile strength(UTS)and yield strength(YS)of thin-walled samples with different thicknesses show minimal differences at both room temperature and high temperature.However,the influence of geometric scale and βgrain size leads to a significant improvement in the total elongation with increasing thickness.Specifically,the elongation of the 4 mm thick specimen is 28.5％(room temperature)and 162％(500 ℃)higher than that of the 1 mm-thick sample.As the thickness of the thin-walled samples decreases,the number of dimples on the fracture surface reduces,while the area of cleavage planes increases,indicating a transition in the fracture mechanism from normal fracture to shear fracture.Meanwhile,the strain hardening rate of the alloy at high temperatures is higher than that at room temperature.This is mainly attributed to the reduction of the critical resolved shear stress(CRSS)of the basal and pyramidal slip systems at high temperature,which promotes dislocation entanglement and thereby enhances the strain hardening capacity.This paper reveals the evolution law of the microstructure and tensile properties of thin-walled structures with thickness,providing theoretical support and technical guidance for the design and manufacture of high-performance thin-walled components in the aerospace field.