A pneumatic-compression composite forming method for rectangular cross-section hollow parts of hard-to-deform materials with rounded corners r≤2t

Abstract

The invention provides an air pressure-die pressing complex formation method of a hard-deforming material and rectangular section type hollow part with a side edge fillet R not greater than 2t, belongs to the technical field of mechanism manufacturing, and specifically relates to a formation method of a hard-deforming material and rectangular section type hollow part. The method aims at solving the problems of high pressure, low inner molded surface accuracy and non-uniform wall thickness in air pressure deformation of a small edge side billet, and low reliability and low molded surface accuracy in welding formation of an existing hard-deforming material and rectangular section type hollow part. The method comprises the following steps: 1, pre-forming a prefabricated blank; 2, sealing a pipe end; and forming under air pressure to obtain a pure expansion pipe; and 3, forming in an air pressure-die pressing complex manner to obtain the rectangular section type hollow part. The method hasthe advantages that the deformation in multi-piece welding process is avoided; the air pressure for fillet formation is reduced; local thinning of the fillet is avoided; the inner molded surface accuracy is improved; and stress concentration danger points are avoided. The method is mainly performed to prepare the hard-deforming material and rectangular section type hollow part with the side edgefillet R not greater than 2t.

Description

technical field [0001] The invention belongs to the technical field of mechanical manufacturing, and in particular relates to a forming method of a hollow member with a rectangular cross-section made of a difficult-to-deform material. Background technique [0002] In hot-end components such as aircraft and rocket engines, titanium alloys or intermetallic compounds are often used to make hollow variable-section components. A typical type of component is as figure 1 As shown, it is a rectangular cross-section member with height variation along the axis ( figure 1 ), which is characterized by small edge fillets and high precision requirements on the inner surface. For example, the outer fillet radius of the edge is required to be R≤2t (t is the wall thickness of the component), the deviation of the internal profile of the component is less than 0.2mm, and the maximum thinning rate of the wall thickness is less than 10%. Since the interior of such components is often washed by...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem of high pressure, poor inner surface precision, uneven wall thickness, poor reliability and low surface precision of the existing hard-to-deform material rectangular cross-section hollow components. to solve the problem, and provide a pneumatic-compression composite forming method for rectangular cross-section hollow parts with edge fillets R≤2t

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