Preparation and characterization of sintered B/MgB₂ as heat release material

Sintered B/MgB₂ (S-B/MgB₂) was originally prepared by introducing Mg to B and sintering the system under appropriate temperature and atmosphere. During the sintering process, B₂O₃ layer was depleted by Mg reduction and the product was characterized by XRD and SEM methods. The XRD results show that the constituents of S-B/MgB₂ are B, B₆O, MgB₂ and MgO. Coupled with EDS, it is noticed that Mg has a desirable distribution in the particles, indicating a uniform configuration of S-B/MgB₂. TG-DSC method was applied to verify the microstructure and study the oxidation processes of S-B/MgB₂. It is noticed that S-B/MgB₂ enjoys a high thermal stability due to the protection from MgB₂/MgO shell. In addition to that, because of the absence of B₂O₃ layer and increased active B content, the length and rate of the oxidation reaction increase, resulting in a boost of reaction ratio and heat release in TG-DSC. Accompanied with theoretical calculation and oxygen bomb test results, it appears that S-B/MgB₂ also enjoys a heat release which is not evidently affected by external conditions. Therefore, S-B/MgB₂ has a promising future as heat release material.