A kind of low-temperature superplastic titanium alloy plate, bar and preparation method

Abstract

The invention provides a low-temperature superplastic titanium alloy plate, rod and preparation method. The chemical composition of the titanium alloy is as follows (% by weight): Al: 5.5-6.5; V: 3.5-4.5; Cu: 4-7; Ti margin. The preparation method of the titanium alloy rods and wires is as follows: smelting in a vacuum consumable furnace to obtain raw material ingots; after the ingots are ground, they are processed into billets by forging and precision forging at a temperature above 1000°C; the billets are processed at 850°C-950°C After a period of heat preservation, it is rapidly cooled to obtain an ultra-fine nano-slab structure; after quenching, the blank is subjected to thermal processing at a temperature of 750°C to 850°C, and the cumulative deformation of thermal processing is greater than or equal to 95%. The texture of the material obtained after processing by this method is equiaxed grains, the size of which is less than 500nm, and the grains do not coarsen and grow within 3 hours of aging at 650°C or below. And the prepared titanium alloy plates and rods with an effective size of 8mm to 30mm are processed at a temperature of 600°C to 850°C and a strain rate of 0.01 to 1s ‑1 It has ultra-high superplasticity, and the elongation rate of the material is 800-1500%.

Description

technical field [0001] The invention relates to the field of titanium alloy processing and preparation, in particular to a low-temperature superplastic titanium alloy plate, rod and preparation method. Background technique [0002] Titanium alloy has good corrosion resistance, low density, high strength, and no magnetism, and is widely used in important fields such as aerospace, biomedical, petrochemical, automotive industry, and marine engineering. Ti6Al4V alloy is a widely used titanium alloy. This alloy has a high yield ratio and is difficult to cold work. However, under superplastic conditions, the alloy will not break even if it undergoes a large deformation range, and the alloy Uniform deformation and high stability. At present, the superplastic forming of titanium alloy has been applied in the aerospace field, such as engine blades, fasteners, etc. [0003] Although superplastic processing has been applied to Ti6Al4V alloy, Ti6Al4V is not the best alloy for superpla...

AI Technical Summary

Problems solved by technology

Materials processed at a lower strain rate at this temperature are severely oxidized and consume high energy, and the mechanical properties of the alloy after forming decrease with the increase of the deformation rate. This is because the grains of the alloy grow up after processing, resulting in different The restraint between the grains is reduced, and the yield strength, tensile strength and elongation after fracture of the material are reduced

Images