Preparation of Mn2AlB2 Material via Thermal Explosion

Abstract

Mn/Al/B mixed powders were used as raw material for the thermal explosion reaction in a tubular furnace to rapidly prepare Mn₂AlB₂ ceramics with high content at low temperature. The effects of raw material ratio, raw material particle size, and NaCl additives on the synthesis of Mn₂AlB₂ were studied systematically. The formation mechanism of Mn₂AlB₂ was proposed. The thermal explosion reaction was induced when the preheating temperature was approximately 686.9°C. The materials with MnB, Al, and Mn₂AlB₂ were synthesized as main phases. Mn₂B and AlMn_x were obtained in small amounts. Increasing the content of Al or refining the Mn and B size in the raw material reduced the content of MnB and other impurities in the product significantly, thereby promoting the synthesis of Mn₂AlB₂. The thermal explosion products were porous, and the sintering degree was weak. Many lathed Mn₂AlB₂ grains with an approximate size of 4 μm were obtained. A mechanism for the thermal explosion synthesis of Mn₂AlB₂ was proposed.