Tantalum alloy sintered strip with Ta-9.2W-0.5Hf composition was used to make alloy ingots by electron beam vacuum melting, then hydrogenation-shatter-dehydrogenation treatment was carried out, 100 mesh ~ 300 mesh powder was obtained after screening, and the surface hardened tantalum alloy powder particles were obtained after multiple low-oxygen partial pressure oxygenation treatment at 300℃ ~ 800℃. The total oxygen content of powder increased from 0.02% to 0.15%. The powder was first formed by cold isostatic pressing, and the relative density of the compact was 65%. Then the cold isostatic pressing compact was put into the tantalum envelope, and the hot isostatic pressing treatment was carried out after sealing and welding. The hot isostatic pressing pressure was 200MPa and the temperature was 1300℃ for 4 hours, and the block material with relative density of 98.8% was obtained. The mechanical properties of the material at room temperature are as following: tensile strength 1303MPa, yield strength 1269MPa, elongation 4.6% and section shrinkage 15%, which are 125% and 164% higher than those of annealed smelted rolled materials with the same composition, and 69% and 76% higher than those of processed smelted rolled materials.
Ta-9.2W-0.5Hf tantalum alloy sintered strip with the same composition as Embodiment 1 is used to form alloy ingots by electron beam vacuum melting, hydrogenation-shatter-dehydrogenation treatment is performed, 100 mesh ~ 300 mesh powder is obtained after screening, and the surface hardened tantalum alloy powder particles are obtained after multiple hypoxia partial pressure oxygenation treatment at 300℃ ~ 800℃. The total oxygen content of powder increased from 0.02% to 0.15%. The powder was first formed by cold isostatic pressing, and the relative density of the compact was 65%. Then the cold isostatic pressing compact was put into the tantalum envelope, and the hot isostatic pressing treatment was carried out after sealing and welding. The hot isostatic pressing pressure was 200MPa and the temperature was 1300℃ for 4 hours, and the block material with relative density of 98.8% was obtained. The relative density of the material was 98.2% after vacuum annealing at 2200℃ for 4 hours. The mechanical properties of the material at room temperature are: tensile strength 865MPa, yield strength 751MPa, elongation 25%, section shrinkage 34%. Compared with Embodiment 1, the strength is decreased, the plasticity is increased, and the strength and elongation are still higher than that of the work-hardened melt-rolled material.
