Effect of Raw Materials on Properties of Coated Al<sub>2</sub>O<sub>3</sub>-Al Cermet Materials via Vacuum Sintering Method

In this paper, the effect of raw materaisl on the properties of coated Al2O3/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 cermet material prepared by the mechanical ball milling method (83.5%) is higher than that of the cermet material prepared by the chemical precipitation method (92.8%). It is nearly 10% lower. The alumina particles prepared by the ball milling method are agglomerated, and a large amount of agglomeration occurs in the aluminum, and the composition is very uneven. For materials prepared by the precipitation method, the aluminum oxide is uniformly distributed in the aluminum. The ball-milling powder is used to prepare materials, most of the alumina is in the form of particles, and in the precipitation method. In the powder preparation sample, the thin layer of alumina which forms the same eggshell envelops the aluminum, and the aluminum has a certain liquid phase change. the surface hardness (824HV) of the cermet material prepared by the mechanical ball milling method is lower than the surface hardness (1005HV) of the cermet material prepared by the chemical precipitation method.