Crystallization and rheological properties of alloys

Abstract

Abstract In the presented work, compressibility is proposed as a property characterizing rheology, i.e. a relative decrease in the volume of liquid metal under the influence of pressure. Compressibility depends on many factors; at a fixed cooling rate, the dependence of compressibility on pressure is established experimentally. The research used industrial equipment for melting metal, pouring it into special equipment, applying pressure to liquid and crystallizing metal according to the program, as well as for recording computer diagrams describing the dependence of compressibility on the magnitude and rate of pressure application. The pressure was varied in the range of 0 … 400 MPa for 4-7 sec, the compressibility value was fixed at the level of 12-13 %. It is also established that the difference in the structure of the B95 alloy formed from a melt pre-pressed under high pressure consists in the absence of pronounced grain boundaries, and in the special character of the release of excess phases, indicating the manifestation of the growth of dendritic cells from the centers of crystallization. The advantages of the developed casting process with high-pressure pressing of liquid metal is a significant reduction of production cycle duration and metal losses, as well as the absence of necessity for processing workpieces by plastic deformation methods.