High-pressure torsion (HPT) superposition manufacturing method and device

Abstract

The invention discloses a high-pressure torsion (HPT) superposition manufacturing method and device. According to the HPT superposition manufacturing method and device, thin discs or circular ring workpieces serve as raw materials; new workpieces are continuously superposed meanwhile HPT deformation is conducted; and metallurgical bonding of the contact surfaces between the workpieces is achieved through further HPT deformation so that the workpieces can be continuously superposed to become a thicker block body, that is, the incremental effect of the workpieces in the thickness direction is achieved till a large-size block body meeting the requirement is machined out, and the obtained large block body metal workpiece is a whole in the true metallurgy meaning. By means of the HPT superposition manufacturing method, the technical defect that the thickness of a workpiece machined through an existing HPT technology is too small is overcome, and meanwhile, the technical advantages that materials which can be machined through high-pressure torsion are wide in range, good in grain refinement effect and low in required deformation temperature, and the size of a workpiece machined through equal-channel angular pressing (ECAP) / back pressure equal-channel angular pressing (BP-ECAP) is large are combined.

Description

technical field [0001] The invention relates to the field of material processing engineering, in particular to a superimposed manufacturing method and device for the preparation of large block ultrafine crystal and nanocrystalline metal materials through the combination of high-pressure torsional severe plastic deformation and incremental processing concepts, which are mainly used in Various metal and alloy materials to realize plastic deformation and incremental processing of these materials under high hydrostatic pressure, so as to control and optimize their structure and improve their performance. Background technique [0002] The severe plastic deformation (SPD) method is a general term for a series of plastic processing techniques with large deformation. The SPD method has an obvious effect of refining grains, and can refine the internal structure of materials to submicron, nanoscale and even amorphous states [R. Z. Valiev. Nature materials. 2004 (3): 511-516.; R.Z. Val...

AI Technical Summary

Problems solved by technology

The technical advantages of this technology are: it can realize metallurgical bonding and process three-dimensional solids of blocks; the material does not melt during processing, the temperature rise is often lower than the recrystallization temperature, no casting defects occur, and the metal properties are not weakened; it is environmentally friendly and safe; at the same time, This technology also has obvious disadvantages: firstly, the ultrasound influence area is limited, and the thickness of the superimposed metal sheets is very small, about 0.1mm; secondly, the ultrasonic vibration indenter, which is the core component of UC equipment, must also have excellent toughness (mechanical in the process of sound wave transmission). loss) and ultra-high hardness (wear resistance), the range of material selection is very limited; again, UC is suitable for processing materials limited, and the strength and hardness of the processed materials must be smaller than the indenter, so that the current process is only applied to aluminum and titanium. In addition, brittle materials are prone to cracks and other processing defects under this process; finally, although this method can achieve metallurgical bonding of metal materials, it has not brought significant grain refinement of metal materials. Performance and physical properties have not been significantly improved

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