方案摘要
方案下载应用领域 | 钢铁/金属 |
检测样本 | 其他 |
检测项目 | |
参考标准 | 亚稳态 |
Thermo-analytical experiments were used to characterize prepared Al?Mg and Al?Ti powders. Ignition temperatures for the Al?Mg powders vary from approximately 860 to 1060 K for the range of heating rates covered in the present ignition experiments. Kinetic correlations using Kissinger analysis were made to identify the reactions that may cause or contribute to ignition. Ignition for both Al?Mg and Al?Ti powders is associated with low-temperature, sub-solidus reactions.
ABSTRACT
Metal powders such as aluminum are commonly used as fuel additives to propellants, explosives, and pyrotechnics because of the improved performance they offer due to their high combustion enthalpies. However, heterogeneous oxidation of metals may cause long ignition delays, high ignition temperatures, low burn rates, and premature extinction leading to an incomplete combustion. Metalbased, mechanically alloyed materials have been proposed to improve ignition and combustion rates as a result of the metastable phase transitions that occur at low temperatures before, and sometimes during combustion. It is of interest to characterize these materials, and specifically, to explore how they behave under inert and oxidative environments upon heating. In this project, high-energy density, Al-based materials (i.e., Al·Mg, Al∙Ti, etc.) are prepared by mechanical milling. Differential scanning calorimetry (DSC) is used to identify and characterize reactions that occur upon their heating in different environments, including subsolidus phase changes, eutectic and pure metal melting, and formation of various oxidized products. Thermogravimetric analysis (TGA) measurements are used to help identify and quantify decomposition and oxidative behaviors. Exothermic reactions observed in DSC are correlated to oxidative weight gains observed in TGA. Kinetic correlations are found using isoconversion processing to identify the reactions that cause or contribute to ignition of the materials. Results of such correlations will be presented in the paper.
利用微量热技术研究病毒结构与宿主细胞受体结合反应
等温量热法研究水泥水化
等温微量热法研究生物制品长时间稳定性评价
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