Different amounts of AlON have been introduced in calcium hexaaluminate(CA_(6)) using two approaches, that is, one-step and twostep methods, to improve the slag resistance of CA_(6). A one-step method can directly sin...Different amounts of AlON have been introduced in calcium hexaaluminate(CA_(6)) using two approaches, that is, one-step and twostep methods, to improve the slag resistance of CA_(6). A one-step method can directly sinter the mixtures combining Al_(2)O_(3), CaCO_(3), and Al in flowing nitrogen, in which AlON clusters are always formed because of the poor wettability of Al by Al_(2)O_(3), leading to the high porosity of CA_(6)/AlON composite. In a two-step method, CA_(6)and AlON are prepared separately and then mixed and sintered in flowing nitrogen. Compared with the sample prepared by the one-step method, CA_(6)and AlON in composite by the two-step method are more uniformly distributed,and the optimized amount of AlON added is 10wt%. The slag corrosion and penetration test shows that the CA_(6)/AlON composite using the two-step method exhibits superior slag corrosion protection. The promoted effect of AlON on slag penetration and corrosion resistance is also discussed.展开更多
以γ-Al2O3为原料,炭黑(C)为还原剂,通过碳热还原氮化(carbothermal reduction and nitridation,CTRN)工艺合成了氮氧化铝(AlON)粉体,并通过气压烧结工艺制备了AlON透明陶瓷.借助X射线衍射分析研究了反应温度、保温时间及碳用量对CTRN...以γ-Al2O3为原料,炭黑(C)为还原剂,通过碳热还原氮化(carbothermal reduction and nitridation,CTRN)工艺合成了氮氧化铝(AlON)粉体,并通过气压烧结工艺制备了AlON透明陶瓷.借助X射线衍射分析研究了反应温度、保温时间及碳用量对CTRN反应产物相组成的影响,借助电子探针研究了AlON透明陶瓷的微观结构.研究结果表明:该反应主要受热力学控制,动力学因素也具有重要作用,反应温度和保温时间对AlON粉体的合成均具有重要影响.在1300℃时,开始发生CTRN反应;随着反应温度的升高,AlN的生成量逐渐增加;在1650℃时,开始形成AlON;在1700℃时,AlON的CTRN合成反应基本完成,产物中除含有极少量的AlN外,其余均为AlON相;进一步提高反应温度至1750℃,产物中残余AlN的量有所减少,但不能完全消除.采用CTRN工艺制备的粉体为原料,经1950℃高温气氛反应6h可制备出AlON透明陶瓷,材料微观结构致密、均匀,平均晶粒尺寸约50μm。展开更多
基金financially supported by the National Science Fund for Distinguished Young Scholars (No. 52025041)the National Natural Science Foundation of China (Nos. 51904021, 51974021, 52174294, and 51902020)+2 种基金the Fundamental Research Funds for the Central Universities (No. FRF-TP-19-008A1)the Project of Liaoning Province’s “Rejuvenating Liaoning Talents Plan”, China (No. XLYC1902092)the Beijing Excellent Talents Foundation。
文摘Different amounts of AlON have been introduced in calcium hexaaluminate(CA_(6)) using two approaches, that is, one-step and twostep methods, to improve the slag resistance of CA_(6). A one-step method can directly sinter the mixtures combining Al_(2)O_(3), CaCO_(3), and Al in flowing nitrogen, in which AlON clusters are always formed because of the poor wettability of Al by Al_(2)O_(3), leading to the high porosity of CA_(6)/AlON composite. In a two-step method, CA_(6)and AlON are prepared separately and then mixed and sintered in flowing nitrogen. Compared with the sample prepared by the one-step method, CA_(6)and AlON in composite by the two-step method are more uniformly distributed,and the optimized amount of AlON added is 10wt%. The slag corrosion and penetration test shows that the CA_(6)/AlON composite using the two-step method exhibits superior slag corrosion protection. The promoted effect of AlON on slag penetration and corrosion resistance is also discussed.
基金supported by the Jiangxi Provincial Natural Science Foundation,China(No.20192BAB216009)the Science and Technology Planning Project of Hunan Province,China(No.2019WK2051)Science and Technology Project of Changsha,Hunan,China(No.kh2003023)。
文摘以γ-Al2O3为原料,炭黑(C)为还原剂,通过碳热还原氮化(carbothermal reduction and nitridation,CTRN)工艺合成了氮氧化铝(AlON)粉体,并通过气压烧结工艺制备了AlON透明陶瓷.借助X射线衍射分析研究了反应温度、保温时间及碳用量对CTRN反应产物相组成的影响,借助电子探针研究了AlON透明陶瓷的微观结构.研究结果表明:该反应主要受热力学控制,动力学因素也具有重要作用,反应温度和保温时间对AlON粉体的合成均具有重要影响.在1300℃时,开始发生CTRN反应;随着反应温度的升高,AlN的生成量逐渐增加;在1650℃时,开始形成AlON;在1700℃时,AlON的CTRN合成反应基本完成,产物中除含有极少量的AlN外,其余均为AlON相;进一步提高反应温度至1750℃,产物中残余AlN的量有所减少,但不能完全消除.采用CTRN工艺制备的粉体为原料,经1950℃高温气氛反应6h可制备出AlON透明陶瓷,材料微观结构致密、均匀,平均晶粒尺寸约50μm。
