(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究一種適于兩步法制備泡沫鋁工藝用新型發(fā)泡劑的熱分解行為，分析其分解過程中的動(dòng)力學(xué)與熱力學(xué)特征，以及發(fā)泡氣體與熔體之間可能存在的反應(yīng)。研究表明：該新型發(fā)泡劑具有分解溫度范圍寬、分解過程緩慢的特點(diǎn)；其在熔體中的發(fā)泡過程主要受化學(xué)反應(yīng)控制；新型發(fā)泡劑所釋放的氧化性氣體與熔體發(fā)生反應(yīng)，在氣泡表面所形成的連續(xù)氧化膜，對穩(wěn)定氣泡形貌、減緩氣泡的合并和長大有重要作用；該新型發(fā)泡劑在兩步發(fā)泡法制備泡沫鋁過程中表現(xiàn)出前期損耗率低、后期發(fā)泡效率高的優(yōu)異性能。
關(guān)鍵字: 泡沫鋁；新型發(fā)泡劑；兩步發(fā)泡法；熱分解行為
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The thermal decomposition behavior of a novel gas-generating agent (NGGA) used for two steps foaming process of aluminum was investigated, its kinetic and thermodynamic characteristics of decomposition reactions, and the potential reactions between the foaming gas and the melt were analyzed. The results show that the novel gas-generating agent has a wide decomposition temperature range and a slow decomposed rate, and its decomposition reactions during the melt are mainly controlled by chemical reaction process. The presence of an oxidizing gas released by NGGA, leads to reactions with the liquid melt, forming a continuous oxide film on the surface of the cell. The presence of the film has a significant effect on the foam stabilization, slowing down cell coalescence and growth. The NGGA exhibits a super performance with a low waste ratio in the former step and a high foaming efficiency in the later step during the two steps foaming process of aluminum.
Key words: aluminum foam; novel gas-generating agent; two steps foaming; thermal decomposition behavior
