Optimization of processing parameters for the Al + 10% B4C system obtained by mechanical alloying

Aluminium matrix composites reinforced with boron carbide are currently employed in the nuclear industry. Homogeneity is the main problem of these composites. The objective of this work is to acquire in-depth knowledge of the Al–B4C system and to manufacture the composite material through powder metallurgy techniques. The processing parameters of the Al + 10% B4C system have been studied in this work. The mechanical alloying process optimization has been carried out in a planetary ball mill up to 12 h. The milling process was systematically studied by taking out powder samples every 2 h. Apparent density and flow rate were measured. Microstructural evolution was analysed using scanning electron microscopy (SEM). Compressibility was measured with the powder obtained by mechanical alloying to establish the optimum compaction pressure. The chosen compaction pressure was 700 MPa. Sinterability was evaluated in N2/10H2/0.1CH4 and argon atmospheres during 30 min at different temperatures. The best results were obtained at 635 °C and argon atmosphere as sintering conditions.