Veronesi Paolo, Rosa Roberto, Colombini Elena, Leonelli Cristina, Poli Giorgio, Casagrande Angelo
Department of Materials and Environmental Engineering, University of Modena and Reggio Emilia, Via Vignotese 905, 41100 Modena, Italy.
J Microw Power Electromagn Energy. 2010;44(1):45-56. doi: 10.1080/08327823.2010.11689769.
A simplified model of the microwave-assisted combustion synthesis of Ni and Al metal powders to form the NiAl intermetallic on titanium and steel substrates is presented. The simulation couples an electro-thermal model with a chemical model, accounting for local heat generation due to the highly exothermic nature of the reactions between the powders. Numerical results, validated by experimental values, show that the capability of microwaves to convey energy, and not heat, can be used to alter the temperature profiles during and after the combustion synthesis, leading to unique intermetallic microstructures. This phenomenon is ascribed to the extended existence of high temperature liquid intermetallic phases, which react with the metallic substrates at the interface. Moreover, microwave heating selectivity allows to maintain the bulk of the substrate metallic materials to a much lower temperature, compared to combustion synthesis in conventionally heated furnaces, thus reducing possible unwanted transformations like phase change or oxidation.
本文提出了一种简化模型，用于在钛和钢基底上通过微波辅助燃烧合成镍和铝金属粉末以形成NiAl金属间化合物。该模拟将电热模型与化学模型相结合，考虑了由于粉末间反应的高放热性质而产生的局部热量。经实验值验证的数值结果表明，微波传递能量而非热量的能力可用于改变燃烧合成期间及之后的温度分布，从而产生独特的金属间化合物微观结构。这种现象归因于高温液态金属间化合物相的长时间存在，其在界面处与金属基底发生反应。此外，与传统加热炉中的燃烧合成相比，微波加热的选择性使得基底金属材料的大部分能保持在低得多的温度，从而减少了诸如相变或氧化等可能的有害转变。
