Magnesium alloy thin wall pipe bidirectional extrusion forming mold and forming method of magnesium alloy thin wall pipe

Abstract

The invention discloses a magnesium alloy thin wall pipe bidirectional extrusion molding mold and a molding method of a magnesium alloy thin wall pipe. The mold comprises a concave mold, an extrusionrod and an extrusion needle, a forward extrusion cavity, a lateral extrusion cavity and a concave mode cavity which communicate with one another are arranged in the concave mold; the extrusion rod comprises a forward extrusion rod and a lateral extrusion rod, the upper end of the forward extrusion rod is connected with a main cylinder of the hydraulic machine, the lower end the forward extrusion rod is matched with the forward extrusion cavity, one end of the lateral extrusion rod is connected with the side cylinder of the hydraulic machine, and the other end of the lateral extrusion rod is arranged in the lateral extrusion cavity and is in clearance fit with the extrusion needle; the shape of one end of the extrusion needle close to the concave mode cavity corresponds to the shape of theconcave mode cavity, and a pipe forming cavity is formed between the extrusion needle and the concave mode cavity; and after a blank is extruded in the forward direction by the forward extrusion rod,the blank is extruded in the direction of the pipe forming cavity by the lateral extrusion rod. The magnesium alloy thin wall pipe bidirectional extrusion molding mold and the molding method of the magnesium alloy thin wall pipe can effectively improve the strength and toughness of the magnesium alloy thin wall pipe after forming.

Description

technical field [0001] The invention relates to a pipe forming process, in particular to a bidirectional extrusion forming die for a magnesium alloy thin-walled pipe and a forming method thereof. Background technique [0002] Magnesium alloy has a series of characteristics such as low density, high specific strength and high specific stiffness. The strength of magnesium alloy is not much different from that of aluminum alloy. Because of its low density, its specific strength is much higher than that of aluminum alloy and steel, and its specific stiffness is not much different from that of aluminum alloy. Magnesium alloys exhibit excellent performance in casting, and magnesium alloy products have good dimensional stability and are suitable for mass production. Environmental protection makes magnesium alloys favored by researchers, and is known as the green engineering material with the most development potential in the 21st century. [0003] Due to the hexagonal close-packe...

AI Technical Summary

Problems solved by technology

[0005] At present, the magnesium industry urgently needs to develop batches of high-performance magnesium alloys, advanced low-cost and low-energy raw magnesium production technologies, and complete sets of technologies for the production of large-scale ultra-thin and complex parts, especially the lack of manufacturing methods for high-performance magnesium alloy thin-walled pipes

The traditional magnesium alloy forming process adopts forward extrusion molding. In this forward extrusion production process, the banded structure and strong basal texture formed along the extrusion direction of the pipe cause the anisotropy of the pipe and reduce the formed pipe. A series of problems such as mechanical properties

Moreover, the basal texture formed after traditional forward extrusion can easily cause defects such as shrinkage cavities and porosity in the light alloy casting structure during the secondary processing of the thin tube, which makes the processing accuracy of the tube, especially the thin tube, worse.

In addition, the transverse section structure of traditional extruded magnesium alloy parts is equiaxed grains, and the longitudinal section structure after extrusion becomes elongated grains, which has a great influence on its mechanical properties.

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