吳建鋒
摘 要:設計了原位生成堇青石結合紅柱石陶瓷的組成,采用無壓燒成法研制了原位生成堇青石結合紅柱石L系列復相陶瓷,探討了提高紅柱石復相陶瓷的抗熱震性能的途徑。研究結果表明:經1400 ℃燒成的L4樣品(紅柱石70%,滑石13%,高嶺土13%,γ-氧化鋁4%)的綜合性能最佳,其吸水率(Wa)為10.71%,氣孔率(Pa)為22.95%,體積密度(D)為2.14 g/cm3;,燒成收縮為2.98%,抗折強度(σb)為92.74 MPa。熱膨脹系數為5.41×10-6/℃,30次熱震實驗(熱震條件:1100℃~室溫,風冷)的強度沒有損失,反而增加了26.20%,常溫導熱系數為1.87 W/(m·K),比熱容為0.90 kJ/(kg·K),儲熱密度為900 kJ/kg(0~1000 ℃)。相組成分析表明樣品的晶相組成為印度石(高溫堇青石),莫來石,硅線石,α-方石英,α-石英等,原位生成的堇青石晶體均勻分布在莫來石晶體之間,賦予樣品較好的抗熱震性能。結果顯示,采用原位生成堇青石結合紅柱石制備的陶瓷材料能滿足太陽能高溫熱發電儲熱材料良好的抗熱震性能,耐高溫,高強度的要求。
關鍵詞:紅柱石 堇青石 儲熱陶瓷 相變材料 儲熱裝置 太陽能熱發電
Abstract:In-situ synthesizing cordierite combined with andalusite was used to improve the thermal shock resistance of the samples. The research showed that formula L4 ( Andalusite 70%, Talcum 13%, Kaolin 13%,γ-Al2O3 4%) fired at 1400 ℃ had the best performance. The properties were listed as followings: apparent porosity 22.95%, water absorption 10.71%, bulk density 2.14 g/cm3, firing shrinkage 2.98%, bending strength 92.74 MPa. After 30 times thermal shock cycles (1100 ℃~RT,air cooling), the loss rate of bending strength of L4 samples was -26.20%. The coefficient of thermal expansion, heat capacity, and thermal storage density of series L4 were 1.87 W/(m·K), 0.90 kJ/(kg·K) and 900 kJ/kg(0~1000 ℃) respectively. The phase composition analysis indicated that cordierite, mullite, sillimanite,α-cristobalite and α-quartz were the phases of samples. Cordierite crystals dispersed in the mullite crystals,and gift samples better thermal shock resistance. The results indicated that the in-situ synthesizing cordierite combined with andalusite ceramics could met the requirements of thermal shock resistance,withstand high temperatures and high strength of heat storage material of solar thermal power generation.
Key Word:Andalusite;Cordierite;Thermal Storage Ceramic;Phase Change Material;Thermal Storage Device;Solar Thermal Power Generation
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