A method for hot reverse extrusion forming of titanium alloy cup-shaped parts

Abstract

The invention relates to a hot reverse extrusion forming method for a titanium alloy cup-shaped part, and belongs to the technical field of hot reverse extrusion forming technologies. The machining method comprises the steps of placing a heated blank into an extrusion container to be subjected to reverse extrusion one-time forming by utilizing the guide positioning action of a material pressing insert, and the roughing blank making step in the forming process of the cup-shaped part is omitted. The material pressing insert guarantees that lugs of the cup-shaped part are flush through the tension action of a back pressure spring; and meanwhile, because a floating male die is in linkage with the back pressure spring with higher back pressure tension, it is achieved that the cup-shaped part can be demolded smoothly after being formed. With the hot reverse extrusion forming method for the titanium alloy cup-shaped part, the phenomenon that in the traditional reverse extrusion process, because one single unloading spring is overhigh in back pressure, the material of a wall of a cup-shaped part flows inwards sharply to tightly hold a male die, and demolding is difficult to carry out is avoided, and meanwhile the reverse extrusion forming force is reduced, and the requirement on equipment tonnage is lowered; and additionally, because a titanium alloy cup-shaped force piece is formed atone time by adopting reverse extrusion in the preparation process, the step of roughing blank prefabrication in the existing technology is omitted, the production period is shortened, the manufacturing cost is reduced, and the economic benefit is greatly improved.

Description

technical field [0001] The invention relates to a hot reverse extrusion forming method for a titanium alloy cup-shaped piece, which belongs to the technical field of forming processing. Background technique [0002] The reverse extrusion processing method is an advanced processing technology with "high efficiency, high quality, low energy consumption, and low cost", which has been widely used in the mass production of various cup-shaped parts. [0003] Due to the large amount of metal in the wall of the cup-shaped part, and the poor formability of the titanium alloy, the deformation resistance is large, and the non-uniformity of the metal flow increases during the reverse extrusion process, which is more likely to cause uneven height of the lugs of the cup-shaped part and uneven distribution of wall thickness. Uniformity makes the qualified rate of cup-shaped parts low and the production cost high. At the same time, it is easier to "hold the mold" after the cup-shaped part ...

AI Technical Summary

Problems solved by technology

[0003] Due to the large amount of metal in the wall of the cup-shaped part, and the poor formability of the titanium alloy, the deformation resistance is large, and the non-uniformity of the metal flow increases during the reverse extrusion process, which is more likely to cause uneven height of the lugs of the cup-shaped part and uneven distribution of wall thickness. Uniformity, so that the pass rate of cup-shaped parts is low and the production cost is high

At the same time, it is easier to "hold the mold" after the cup-shaped part is reverse-extruded, and cannot be separated from the punch

In addition, the traditional forming process often needs to upset the preform to meet the deformation requirements of the part in the forming process of the cup-shaped part. The process requires a lot of man-hours and low production efficiency.

[0004] In order to prevent uneven cup lugs and rapid unloading after cup-shaped parts are formed, the patent "A Back-pressure Extrusion Die and Processing Technology Using the Die" (application publication number CN105414233A) adopts a single-size back Compressing the spring causes the reverse extrusion forming force to rise sharply in the later stage of cup-shaped parts forming, which increases the load and tonnage requirements of the equipment, and at the same time increases the wear of the mold

[0005] In order to avoid the phenomenon of the mold holding of the cup-shaped part after the back-extrusion is completed, the patent "Manufacturing method of blowout preventer cylinder and the back-extrusion die used therein" (application publication number is CN103909110A) is provided with a release at the opening of the back-extrusion die. For the material plate, after forming, the forging is stopped at the lower side of the stripper plate. Although this method can realize the smooth demoulding of the forging, it cannot ensure that the lug height of the cup-shaped part is even at the same time.

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