利用莫来石陶瓷与AlSi_(12)合金制备相变储热材料的研究

Study and preparation of phase change material for thermal storage using mullite and AlSi_(12) alloy

以莫来石陶瓷和AlSi_(12)合金为原料,合成一种新型的相变储热材料。分析服役期间相变储热材料的物理化学性质,及其相组成、显微结构的变化规律,并探讨AlSi_(12)合金的氧化损坏对相变储热材料储热性能的影响。分析结果表明:经莫来石陶瓷封装的AlSi_(12)合金具有优良的抗氧化性,持续服役1 000 h后,AlSi_(12)合金的氧化增重率仅为3.75%;服役期间,AlSi_(12)合金中部分Al元素被氧化成Al_2O_3,导致了AlSi_(12)合金的相变温度范围变窄,储热量随之减小,从而影响了AlSi_(12)合金的储热性能;AlSi_(12)合金不会严重腐蚀莫来石陶瓷,也不会向莫来石陶瓷渗透,且部分Al_2O_3积聚在莫来石陶瓷表面,从而降低了AlSi_(12)合金在服役后期的氧化速度。研究结果为利用AlSi_(12)合金制备相变储热材料提供参考。

A new phase change heat storage material was synthesized from mullite ceramics and AlSi12 alloy.The physical and chemical properties,phase composition and microstructure evolution of phase change heat storage materials during working were analyzed,and the effect of oxidation damage of AlSi12 alloy on the thermal storage properties of phase change heat storage materials was discussed.The results showed that AlSi12 alloy encapsulated by mullite ceramics had excellent oxidation resistance,and the oxidation weight gain rate of AlSi12 alloy was only 3.75%after working for 1 000 h.During working,part of Al element in AlSi12 alloy is oxidized to Al2O3,which results in the narrowing of phase transformation temperature range and the decrease in heat storage capacity of AlSi12 alloy,thus affecting the thermal storage performance of AlSi12 alloy.The alloy would not seriously corrode the mullite ceramics,nor would it penetrate into the mullite ceramics,and part of Al2O3 accumulates on the surface of the mullite ceramics,which reduced the oxidation rate of AlSi12 alloy in the later working period.The results provides a reference for the preparation of phase change heat storage materials using AlSi12 alloy.