Influence of Molding Pressure on Properties of Al_2O_3-AI Composite Materials Sintered via Vacuum Sintering Method

摘要

In this paper, the effect of raw materaisl on the properties of coated Al_2O_3/Al cermet materials were investigated, the raw materials were prepared via different methods, which provide a reference for obtaining higher performance cermet materials. Through mixing, molding, sintering, sample preparation, scanning electron microscopic observation, energy spectrometer observation and analysis, the following conclusions can be drawn, the density of the composite material increases first and then decreases with the increase of the molding pressure. When the molding pressure is 30 MPa, the density of the composite material reaches the maximum value, that is 93.5%. The greater the applied pressure, the more compact the aluminum powder and alumina powder, and the longer the tissue composition, the more uniform, there is no crack in the c-picture, and there are cracks in the a and b pictures. The microstructure of metal matrix composites prepared at different molding pressures is also different. Sintering of the green body formed at 30 MPa resulted in relatively few cracks and voids in the material. The surface hardness of the composite material increases first and then decreases with the increase of the molding pressure, and the surface hardness of the composite material reaches a maximum value (875 HV) at a molding pressure of 30 MPa.