Hot isostatic pressure near-net forming method for semi-solid complex difficult-machining compact piece

A hot isostatic pressing and near-net-shaping technology, which is applied in the manufacture of aerospace parts with complex structures, and in the field of parts with difficult-to-process and complex-shaped static-pressed materials, which can solve the problems of easy-to-produce pores, excessive sheath deformation, and microstructure Coarse and other problems, to achieve the effect of easy deformation and flow, avoid performance defects, fine and uniform structure

CN105772726AInactive Publication Date: 2016-07-20HUAZHONG UNIV OF SCI & TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2016-07-20
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a hot isostatic pressure near-net forming method for a semi-solid complex difficult-machining compact piece. The hot isostatic pressure near-net forming method comprises the steps that a semi-solid material is used as a forming material, graphite is used as an internal form control core, the hot isostatic pressure temperature is selected as the solid-liquid two-phase interval temperature, and the compact piece in a complex shape is directly formed under coupling of temperature and pressure. According to the hot isostatic pressure near-net forming method for the semi-solid complex difficult-machining compact piece, performance defects caused by powder surface pollutants in traditional methods can be effectively overcome, and the part forming precision can be effectively ensured through high pressure at the high temperature; in addition, the temperature close to the melting point of an alloy material is adopted, and a solid-liquid coexisting phase occurs in a ladle sleeve at the temperature; due to the fact that liquid phase components exist among crystal grains or solid phase particles, the solid phase particles almost have no binding force and are very low in flow deformation resistance, and a complex runner in the form control core is filled with parent metal advantageously; and moreover, the solid phase particles are easy to separate on specification portions, and while, due to the fact that the liquid phase components exist, the separated portions are very easy to connect integrally.
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Description

technical field

[0001] The invention belongs to the field of advanced manufacturing, and in particular relates to a method for near-net hot isostatic pressing of semi-solid complex and difficult-to-machine dense parts, which is used for parts with difficult-to-machine and complex shapes of hot isostatic pressing forming materials, and the method is especially suitable for manufacturing aerospace Parts with complex structures. technical background

[0002] Nickel-based and titanium-based alloys are widely used in aerospace because of their good comprehensive properties. Nickel-based alloys have the characteristics of good thermal fatigue resistance, low thermal expansion coefficient, and high elastic modulus, and are widely used in hot-end parts such as aerospace engines and industrial gas turbine turbines; titanium alloys have high specific strength, high thermal strength and durability Strength, low crack growth sensitivity under vibration load and impact load, and good co...

Examples

example 1

[0039] This is to utilize the present invention to make nickel alloy (inconel625) blisk ( image 3 ) instance:

[0040] The melting point of Inconel625 is 1290°C to 1350°C, so the thermal isostatic process parameters this time are temperature 1300°C and pressure 120MPa; increasing the temperature first and then boosting the pressure is more accurate in size and mechanical properties than the simultaneous temperature increase and pressure increase. Therefore, this hot isostatic pressing chooses the process method of raising the temperature first and then raising the pressure.

[0041] Against this background, the above-mentioned problems can be solved by using the present invention. Specific steps are as follows:

[0042] (1) According to the structure of the blisk, the hot isostatic pressing forming sheath and the shape-controlling core are designed. The sheath is mainly composed of a cylinder, a lower cover and an upper The distance is arranged in a ring shape and consists...

example 2

[0053] This is to use the present invention to adopt titanium alloy semi-solid material (Ti6Al4V) to manufacture long straight structural parts ( Image 6 ) instance:

[0054] The melting point of Ti6Al4V is about 1660°C, so the process parameters of this hot isostatic process are temperature 1600°C and pressure 120MPa.

[0055] Against this background, the above-mentioned problems can be solved by using the present invention. Specific steps are as follows:

[0056] (1) According to the design of the parts, the hot isostatic pressing forming jacket and graphite core are selected as the jacket material of No. 45 steel;

[0057] (2) Design the semi-solid CAD model of the prefabricated Ti6Al4V alloy according to the remaining dimensions in the sheath after the sheath and the shape-controlled core are assembled;

[0058] (3) Machining methods are used to process the sheath, graphite, and semi-solid Ti6Al4V models respectively, and assemble them;

[0059] (4) Weld the sheath, a...