A hot isostatic pressing method for improving the surface quality of parts

Abstract

The invention discloses a hot isostatic pressing forming method used for improving the part surface quality. The hot isostatic pressing forming method comprises the following steps that three-dimensional models of a wrapping sleeve and a shape control die core are designed according to the shape and size of a formed part; the stainless steel wrapping sleeve and the carbon steel shape control die core are manufactured according to the manufactured three-dimensional models; a ceramic coating is sprayed on the surface of the shape control die core through a physical vapor deposition (PVD) method; the shape control die core is fixed in the wrapping sleeve, and the wrapping sleeve is filled with powder and shaken to be compacted; the wrapping sleeve is subjected to air exhausting and heating treatment, sealing welding is conducted when the vacuum degree in the wrapping sleeve reaches a certain degree; the wrapping sleeve is subjected to hot isostatic pressing treatment through a technique that the temperature is increased at first and then the pressure is increased so as to make the powder be tightened and compacted under the action of the high temperature and the high pressure; and the wrapping sleeve and the shape control die core are removed to obtain the final part. According to the hot isostatic pressing forming method, the carbon steel die core with the coating serves as the shape control die core, and element diffusion between carbon steel cores and the powder can be effectively prevented; element segregation of the alloy surface due to diffusion is avoided, and the alloy surface quality is improved.

Description

technical field [0001] The invention belongs to the field of hot isostatic pressing, and more specifically relates to a hot isostatic pressing method for improving the surface quality of parts. Background technique [0002] The high-temperature parts of key parts such as working blades, turbine discs, and combustion chambers of aero-engines have extremely strict requirements on materials. They not only require good high-temperature oxidation and corrosion resistance, but also require high-temperature strength, creep Strength and durability and good fatigue properties. Nickel-based alloys and titanium alloys are widely used in the aerospace field because of their good comprehensive properties. Nickel-based alloys have good thermal fatigue resistance, low thermal expansion coefficient, high elastic modulus, etc., and have good high-temperature oxidation resistance and corrosion resistance. Nickel-based superalloys generally work above 600 ° C and withstand certain stress cond...

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Problems solved by technology

[0004] However, in the prior art, when conventional materials are used as control cores, under the action of high temperature and high pressure, the elements of powder particles and the control cores tend to diffuse, resulting in changes in the content of elements on the surface of the part after forming, and some elements pass through the diffusion process. The effect is transferred to the surface of the shape-controlled core, and at the same time, some elements on the surface of the shape-controlled core diffuse to the surface of the formed part. This phenomenon leads to uneven distribution of alloy elements and reduces the surface quality of the part.

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