Study On Microstructures And Properties Of High Property Copper Based Alloy Fabricated By High Pressure Torsion

Material plays a decisive role both in human life and in human development.Copper-based alloy, which is one of the earlier material human used, still occupies animportant place in today’s high-speed development of society. It is widely used in electricpower, automotive, defense, home appliances, communications and other fields, andbecomes an indispensable material.DEFORM-3D finite element software is used to simulate the forming of the powdermaterial using restrictive mold by high pressure torsion. The effects of the technologicalparameters to its equivalent strain are mainly studied. The results show that the impact ofequivalent strain is small while the friction factor is small, and that equivalent strainsignificantly increased while the friction factor reaches a certain value. With the pressureincreasing, the equivalent strain increases gradually. With the number of turns increasing,the equivalent strain increases gradually, and equivalent strain distribution becomes moreuniform. With the thickness of fully densification in theory increasing, the equivalent straindecreases gradually.Restrictive high-pressure torsion mold is used in this study. The experiments aredone by controlling one single factor. The efforts of the key factors, such asforming pressure, the number of turns, the thickness of fully densification andtemperature, to copper and aluminum composite power forming by high pressuretorsion are studied. And the influencing regularities of key forming factors tomicrostructure, relative density and microhardness of copper-aluminum material areobtained and investigated. The experiments show that the influencing regularities offorming pressure, the number of turns and temperature are almost the same tocopper-aluminum material by HPT. Increasing pressure, the number of turns and certaindegree of temperature increasing can reduce the porosity, refine microstructure, promotethe permeation and fusion of microstructure of copper and aluminum, and improve its property of the specimen. While the thickness of fully densification in theory just behavethe opposite. The change tendency of the microhardness and the DEFORM-3D numericalsimulation equivalent stain have a certain similarity. The DEFORM-3D numericalsimulation has a certain reference value.Two high pressure torsion specimen are selected to do tensile test, and tensile fracturesurfaces are observed by scanning electron microscope to investigate the tensile fracturebehavior. The results revealed that the fracture is mixed fracture. The deformation behaviorand densification of the powder particles are analysed in copper-aluminum materialforming process by high pressure torsion. It shows that the micromechanism of themovement, the plastic deformation and the densification of the power including thedisplacement of the powder particles, rotation, and elastic deformation, plastic deformationand pore deformation and so on.