Synthesis of magnesium diboride powder by self-propagating high-temperature

Self-propagating high-temperature synthesis (SHS) method was used to fabricate MgB2 powder from Mg-B system. In this paper, the reaction process of Mg with B was studied by thermodynamic calculation, X-ray diffract-meter and micro-image analyzer. These results show that the single-phase MgB2 can be synthesized by self-propagating high-temperature synthesis method. When Mg reacts with B, Mg firstly melts and then reacts with B to form MgB2; but if the synthesis temperature is too high, MgB2 can decompose into MgB4 and Mg. These synthesized MgB2 particles appear random geometry and fine crystal grain. At normal pressure, the decomposition temperature of MgB2 is less than 1320K; but higher gas pressure is beneficial to lifting the decomposition temperature of MgB2. And at high temperature, there are these phenomena that MgB2 can also exist or MgB2 directly decomposes into Mg and amorphous B.