Manufacture and Performance of the Al₂O₃/Al Compound Powder and Cermet with the Powder Metallurgy

Abstract

On the one hand, cermet has the advantages of metal materials, and on the other hand, it maintains the excellent properties of ceramic materials, and is a very important new engineering material. In this paper, the alumina/aluminum cermet material composite powder was prepared by ball milling, and its densification properties were characterized and studied to provide reference for the preparation of high-performance cermet materials. When the ball milling time is more than 6h, the distribution of alumina particles around the aluminum powder is relatively uniform. The research shows that: with the extension of the ball milling time, the number of pinning of Al2O3 particles on the surface of the Al ball first increases and then decreases; The trend of decreasing; with the increase of ball-to-powder ratio, the distribution of Al2O3 particles on the surface of Al balls is more uniform. Considering its cost-effectiveness, it is more suitable to prepare pinned alumina/aluminum-ceramic composite powder under the conditions of ball milling speed of 360r/min, ball-to-material ratio of 2:1 and ball milling time of 12h. When the Al content gradually decreased, the density and hardness of the cermet material also decreased gradually. When the Al content gradually decreased, the density and hardness of the cermet material also decreased gradually. When Al accounts for 75% in the sample, the microstructure is dense and the hardness is higher. When the molding pressure is 20MPa, the unevenness of the surface of the material is greatly relieved, relatively flat, and the densification effect is better. When the sintering temperature is 800°C, the fired sample is very dense, and the particles have relatively high bonding strength, but a small amount of aluminum is precipitated on the surface of the sample, forming a silver-white spherical substance.