Concentrated solar power used in preparation of Ti – B4C composites

Abstract

Concentrated solar power was employed to sinter compacts of Ti + 15 vol% B4C powder mixture. The sintering experiments were performed under protective argon atmosphere at different temperatures and sintering time without external pressure. The sintering experiments were done in 40 kW horizontal solar furnace (SF40) at Plataforma Solar de Almeria (PSA), Spain.The in situ sintering behavior of the Ti – B4C mixture is significantly affected by exothermic reaction of titanium with B4C. In the solar furnace the ignition temperature of this reaction was found to be around 1380 °C. Therefore, the exothermic reaction of Ti + B4C makes the controlling of the solar sintering of these composites very difficult.The optimal temperature of solar sintering was found slightly below 1340 °C for 30 min. No significant reduction of porosity was observed: All samples have more or less the same final porosity value as green compacts prior sintering. The prepared composite samples are brittle. Decomposition of boron carbide led to the creation of TiB2, TiC and complex TiBxC1-x phases which were confirmed by microstructural investigations.