Hot isostatic pressing two-step forming method of high temperature alloy compact piece

Abstract

The invention belongs to the field of advanced manufacturing, and particularly relates to a hot isostatic pressing two-step forming method of a high temperature alloy compact piece. The method includes two steps of hot isostatic pressing, according to a first step of hot isostatic pressing, a formation control mold is controlled to deform at a low temperature or pressure, part pressed blanks high in precision of shapes and sizes are obtained, wrapping sleeve limitation does not exist in a second forming step, the temperature and the pressure which are most suitable for formation material are adopted, both holes left in the first step are eliminated, compactness is improved, and the precision of the shapes and the sizes is guaranteed, and good organizational performance under the most suitable temperature and the most suitable pressure is obtained. Due to the fact that the temperature and the pressure in the first forming step are low, material choosing problem of complicated formation control molds is solved, material which is difficult to process and high in high temperature yield strength is not required to be chosen as a formation control type mold core, and manufacture cost of the mold is reduced.

Description

technical field [0001] The invention belongs to the field of advanced manufacturing, and in particular relates to a hot isostatic pressing two-step forming method for high-temperature alloy dense parts. technical background [0002] Some key components in the aerospace field are often processed from high-temperature alloys (nickel-based alloys, titanium-based alloys) and other difficult-to-machine materials. Conventional methods are used to process and form them. The process is difficult, the material is wasted, and the manufacturing cost is high. [0003] Nickel-based titanium-based superalloys are irreplaceable forming materials for aerospace high-temperature hot-end parts because of their good fracture toughness, fatigue resistance, hot corrosion resistance and good high-temperature strength. However, the complex alloying of superalloys leads to severe composition segregation, dispersion of mechanical properties, and deterioration of thermal process properties during cast...

AI Technical Summary

Problems solved by technology

The following basic principles must be followed in the selection of sheath material: (1) The sheath should have absolutely reliable airtightness; (2) It should not react with the pressed material; (3) It has appropriate strength and good plasticity; (4) It is easy to Processing and forming, easy to peel; (5) has good economic effectiveness. Based on these principles, the choice of wrapping materials is limited to a certain extent

[0008] At present, most of the hot isostatic pressing sheaths are made of mild steel, because mild steel has good processing performance, easy to remove after hot isostatic pressing, and the price is relatively cheap, but due to the low high temperature yield strength of mild steel, it is used as In the shape control part of the sheath, large deformation occurs under high temperature and high pressure environment, it is difficult to guarantee the original shape, and the dimensional accuracy and shape accuracy of the final formed part cannot be guaranteed

[0009] In addition, in the complex structure and long straight structure of the part, it is difficult for the powder to achieve densification under the driving force of the sheath deformation, and it is easy to generate pores, so that the performance of the part cannot meet the requirements

If the pressure is increased to increase the driving force, the sheath may deform too much and crack

Therefore, in hot isostatic pressing parts, there are porosity defects in complex structural parts and long straight parts

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