Equal-passage variable-cross-section extruding mold and extrusion forming method for pipes

Abstract

The invention relates to an equal-passage variable-cross-section extruding mold and an extrusion forming method for pipes. The equal-passage variable-cross-section extruding forming is adopted, so the extruding forming of the pipes is formed through the twisting shearing deformation and the upsetting deformation on the cross section, and the combination of various deformation modes in one extruding process is realized. The pipe walls are in a strong three-direction press stress state through being limited by die cavities and polyurethane foam filling agents, in the deformation stage of circle-ellipse-circle and ellipse twisting change, materials enter twisting shearing deformation zones of the metal transition regions, the material internal tissues generate rotation and shearing stress under the effect of the shearing stress, the orientation of the material tissue structure is caused, i.e. a new tissue structure is formed, and the material tissue structure under the same deformation degree is improved. The mold and the method have the advantages that deformation degree higher than that of the traditional forming process can be obtained, the strain distribution and the stress distribution inside the pipes are improved, residue casting tissues of the pipes can be favorably crushed, the forms and the distribution of inclusions are changed, and the internal tissue defects of the pipes are eliminated.

Description

technical field [0001] The invention relates to the field of forming metal pipes such as aluminum, copper, steel, etc., in particular to an equal-channel variable-section extrusion die and an extrusion forming method. Background technique [0002] The use of pipe fittings and sleeves is all involved in the fields of aviation, aerospace, automobiles and mechanical equipment. Taking an aircraft as an example, the pipeline system is the lifeline of the aircraft, and its performance directly affects the overall performance of the aircraft. If the engine is compared to the heart of the aircraft, then the pipeline is like the blood vessels of the aircraft. Therefore, it is very important to improve the technical level of the pipeline system to improve the performance of the aircraft. [0003] At present, most metal pipes used in pipeline systems on the market adopt traditional forming methods, and most of them are seamless pipes (Baogang Science and Technology, 2002, 2: 21). The...

AI Technical Summary

Problems solved by technology

[0006] The above-mentioned traditional pipe-making process is difficult to meet the needs of the growing aviation industry. Due to insufficient strength and the influence of deformation texture, cracking will occur during use, which will affect the safety and reliability of aircraft pipelines in severe cases.

Images