Study of Structure and Mechanical Properties of Long-Length Metalware from D19 Alloy Produced by Continuous Casting and Deformation of Metal in Solid-Liquid State

摘要

A new method of metal ware production in conditions of the combination of continuous casting and metal simultaneous deformation in solid-liquid state is considered in this paper. The microstructure and mechanical properties of the obtained metal products from alloy D19 are investigated. This method of continuous casting is developed for production of long-length metalwares having improved mechanical and performance properties. The processing of D19 alloy enhances the strength and ductility characteristics in the fabricated metal by using this technology. It is shown that the obtained metalwares have a fine-grained directional structure. The grain boundaries are uneven and wide and consisting of a plexus of dislocation loops and grids. This internal structure is formed immediately during the crystallization process and provides increased mechanical characteristics. After leaving the crystallizer, metalwares from D19 alloy have the following mechanical characteristics: temporary tensile strength ≈290 MPa, yield strength =172 MPa, Brinell hardness ≈823 MPa, relative elongation of 25%. It is established that the considered technology and implemented device allow for a short production cycle to obtain metalwares from aluminum alloys with high mechanical properties without additional processing. The disadvantages of the existing laboratory device are attributed to the presence on the surface of the workpiece of periodic traces of movement of the moving walls of the crystallizer. However, this is a defect of the device, not the technology, and it will be eliminated. The presented constructive solution is a small-sized installation that does not require large production areas. When implementing this process, there is no need for furnaces to maintain the temperature of the workpiece in the required range, for example, in accordance with the requirements of the rolling process.