Laser rapid forming of low cost hydride-dehydride titanium alloy powder
(1.陕西省西安市西北工业大学凝固加工国家重点实验室
2.State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
2.State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: Low cost hydride-dehydride (HDH) Ti-6Al-4V (Ti-64) alloy powder was employed to investigate the metallurgical quality and mechanical properties of laser formed samples. With appropriate control of the laser forming processing parameters and the loose density of HDH powder, two kinds of defect, i.e. porosity and ill-bonding, can be avoided. Rare earth Nd powder was added to HDH Ti-64 powder to purify laser formed alloy. The results show that with a few additive of Nd, the microstructure of laser formed alloy changes from Widmanst？tten morphology to a basket weave microstructure. Accordingly an appropriate addition of Nd is effective to improve both the strength and ductility of laser formed HDH Ti-64 alloy. The values of tensile test meet the wrought specification with the content of Nd ranging from 0.1%？0.2%(mass fraction).
Key words: laser rapid forming; hydride-dehydride titanium alloy powder; rare earth Nd; microstructure; mechanical properties