3D super-plasticizing treatment method and superplasticity precision shaping method for magnesium alloy

Abstract

The invention discloses a 3D super-plasticizing treatment method and superplasticity precision shaping method for magnesium alloy. Within the superplastic deformation temperature range of the magnesium alloy, a non-hollow magnesium alloy casting obtained after forging pretreatment passes through at least two cycles to obtain a forging stock of the set size, and 3D super-plasticizing treatment is finished, wherein the non-hollow magnesium alloy casting passes through the axis Z, the axis X and the axis Y in sequence to press down the stock to achieve a cycle. By means of 3D super-plasticizing forging treatment, through large plastic deformation in all directions, homogenizing, grain refining and structure densifying of materials are fully achieved, refined grains are averagely smaller than 20 microns, the equiaxial grain refining effect is remarkable, and the strength performance of the casting can be greatly improved. Through the superplasticity precision shaping method for the magnesium alloy based on 3D super-plasticizing treatment, a light magnesium alloy transition car coupler with high strength is prepared out; and compared with an existing transition car coupler, the weight is reduced by about 75%, the strength is above 350 MPa, and the requirement for the service life of the transition car coupler of this type can be met.

Description

technical field [0001] The invention belongs to the technical field of short-process rapid prototyping of new materials, and relates to a magnesium alloy 3D superplasticizing treatment method and device, a magnesium alloy superplastic precision forming method based on the treatment method, and a transition coupler processed by the forming method. Background technique [0002] The transition coupler is the core component connecting the rail train, and it is also an extremely important safety structure. It is commonly used in the process of marshalling, rescue, shunting, etc. of subway trains, trams (low-floor trains), ordinary passenger trains, and high-speed EMUs. The tool needs to be manually transported to the position of the coupler at the end of the vehicle for manual installation during return and rescue. There is no auxiliary borrowing mechanism, so a lightweight design for the transitional coupler is required. For the subway, its marshalling frequency is high, and tra...

AI Technical Summary

Problems solved by technology

Transition couplers made of carbon fiber have been trial-produced by British Railways, but the cost is too expensive, hundreds of times that of existing steel couplers, and it is difficult to promote in Europe. will inevitably decay over time, resulting in a gradual decrease in reliability performance

High-strength low-alloy steel transition couplers are mainly produced by casting or welding, with low reliability, high quality, and difficult operation. They are eliminated technologies and products

[0006] To sum up, most of the currently used transition couplers are made of cast steel, and the manufacturing cost of the newly developed transition couplers made of carbon fiber is too expensive to be put into practical use.

The steel transition couplers used at this stage have the following technical defects: (1) heavy weight, difficult manual movement and alignment; (2) low structural strength; (3) low manufacturing precision, difficult to form complex microstructures, and require follow-up A large number of mechanical processing to achieve precision molding; (4) The surface quality of cast molding products is poor

[0008] In addition, the molding and processing technology of lightweight and high-strength materials with practical significance is not yet mature, and high-efficiency molding methods have not yet appeared, which is also an important issue in current research in this field

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