Sintering and mechanical properties of AlMgB14 composite materials

Different AlMgB14 composite materials were prepared from pre-reacted AlMgB14 and starting elemental powders by hot pressing. Only slightly different densification behaviours were found for the two types of starting materials. Full densification without decomposition was achieved only with a hot pressing pressure of 75 MPa. Different additives were tested to improve densification. The influence of the additives on the densification was found to be minor. A strong increase in hardness was observed for materials with Si, TiC, WC, TiB2 additions. The carbides react with the AlMgB14 during sintering, forming TiB2 and WB2 or their solid solutions.