Large-deformation composite extrusion preparation method for magnesium alloy profile for vertical hydraulic machine

Abstract

The invention discloses a large-deformation composite extrusion preparation method for a magnesium alloy profile for a vertical hydraulic machine. The large-deformation composite extrusion preparationmethod comprises the steps that (1) blanking is conducted; (2) homogenization treatment is conducted; (3) a blank and a die are heated and subjected to heat preservation; (4) a lubricant is smeared,and the blank is placed into a forward extrusion cavity; (5) the blank is forwards extruded into a storage cavity through a calibrating straight; (6) the blank continuously bears pressure to flow tillmaking contact with the bottom of the storage cavity, the blank radially flows, the space in the storage cavity is gradually and fully filled with the blank, and in the process, the blank is subjected to upsetting deformation; (7) under the downward pressing effect of the male die, blank metal starts to flow towards a radial cavity extrusion opening communicating with the two sides of the storagecavity to be subjected to lateral extrusion deformation, and when the stroke of the male die is completed, the lateral extrusion process is also completed; and (8) die release is conducted. Accordingto the large-deformation composite extrusion preparation method, one-time forming of large plastic deformation of forward extrusion, upsetting and lateral extrusion is achieved, thus the strain amount is increased, the stress strain state is enriched, the structure is improved, the structure strength is weakened, production processes are effectively reduced, and the large-deformation composite extrusion preparation method adapts to market economic prospects in China.

Description

technical field [0001] The invention belongs to the technical field of plastic processing and forming of metal materials, in particular to a large-deformation composite extrusion preparation method of a magnesium alloy profile for a vertical hydraulic machine. Background technique [0002] Magnesium alloy is the lightest structural material in engineering applications. It has high specific strength and specific stiffness. However, magnesium alloy has less room temperature slip system and poor high-temperature mechanical properties, which limit its wider application in the engineering field. By plastically deforming magnesium alloys (such as extrusion, upsetting, rolling, etc.), the grains of the structure can be refined, and the mechanical properties at room temperature and high temperature can be significantly improved. Magnesium alloy profiles are widely used and in great demand. At present, the main method for forming magnesium alloy profiles is forward extrusion. The ou...

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Problems solved by technology

The outflow direction of the profile in forward extrusion is the same as the extrusion axis, which has the advantages of simple operation, high production flexibility, and large cross-sectional span of the extrusion, but it also has disadvantages. On the one hand, the profile is subjected to The frictional resistance is large, and the metal flow is uneven, resulting in a large difference in the performance of the head and tail of the extruded parts, and the magnesium alloy profiles obtained by purely forward extrusion are less plastic deformation and have a single stress-strain mode. This leads to coarse grains and poor comprehensive mechanical properties; on the other hand, in the existing production of magnesium alloy profiles, profiles with large axial dimensions are often realized by using horizontal hydraulic presses, while vertical hydraulic presses in my country Occupancy far exceeds that of horizontal hydraulic presses, so most of the actual production conditions in my country are still dominated by vertical hydraulic presses. In order to adapt to the actual production conditions of our country, and on this basis, focus on strengthening the mechanical properties of magnesium alloys, the applicant Specially proposed a large-deformation composite extrusion preparation technology for high-strength and tough magnesium alloy profiles applied to vertical hydraulic presses

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