作　　者： ; ; ; ;

机构地区： 中南大学材料科学与工程学院粉末冶金国家重点实验室

出　　处： 《中南大学学报（自然科学版）》 2008年第5期980-986,共7页

摘　　要： 以聚乙烯醇(PVA)和NiFe2O4/Ni型金属陶瓷压坯为对象,采用热重分析(TGA)研究PVA在N2气氛中的热脱脂行为,建立PVA热脱脂速率的数学模型,在此基础上,模拟并计算PVA分解产物气体在多孔粉末压坯内的压力构建情况;结合粉末压坯脱脂强度测试结果,分析粉末压坯在脱脂过程中压坯尺寸、粘结剂含量等因素对升温速率和脱脂时间的影响,获得不同半径尺寸压坯的极限升温速率。运用所得方法和所得极限升温速率结果进行脱脂实验升温制度设计,实现了压坯直径D=0.12 m,压坯厚度e=0.12 m的NiFe2O4/Ni惰性阳极大型压坯的无缺陷热脱脂。 For developing non-defects large scale NiFe2O4/Ni cermet compacts of inert anode for the primary aluminium industry, the thermo-gravimetrie analysis was used to determine the thermal degradation kinetic of poly（vinyl alcohol） which was used as a binder. The kinetic parameters were then used in a coupled transport and kinetic model for evaluating the buildup of the gas pressure within the large scale ceramic green body as a function of variations of the heating rate and the body dimension. The critical heating rate for different body radius was predicted by comparing the gas pressure when the peak degradation rate occurred with the threshold body strength which was determined by the diametric compression test of the green body during thermal debindering. The results show that using these methods to design the thermal debinder process of NiFe2O4/Ni inert anode green body with binder diameter of 0.06 m and binder thickness of 0.12 m, the non-defects debinded and pre-sintered samples are gained after a 2 460 min heating up process.

关 键 词： 惰性阳极 热脱脂 极限升温速率

领　　域： [化学工程] [一般工业技术]