(1. 中南大學 粉末冶金國家重點實驗室,長沙 410083;2. 中南大學 冶金科學與工程學院,長沙 410083)
摘 要: 研究以PVA為主要成分的粘結(jié)劑體系的熱分解特性對大尺寸粉末壓坯脫脂行為的影響,發(fā)現(xiàn)PVA的不均勻熱分解是造成大尺寸粉末壓坯脫脂失效的原因之一,開發(fā)一種具有穩(wěn)定熱分解反應特性的新型粘結(jié)劑體系,實現(xiàn)大尺寸粉末壓坯的無缺陷熱脫脂;研究燒結(jié)氣氛、金屬相的添加對NiFe2O4-10NiO致密化行為的影響。結(jié)果表明:N2氣氛燒結(jié)及加入Ni可有效提高NiFe2O4-10NiO陶瓷基體的燒結(jié)致密度,1 350 ℃時于N2氣氛中燒結(jié)的NiFe2O4-10NiO/5Ni型金屬陶瓷材料的相對密度達到97.28%。采用優(yōu)化工藝實現(xiàn)d 120 mm×140 mm深杯狀NiFe2O4-10NiO/17Ni金屬陶瓷惰性陽極脫脂預燒坯的燒結(jié),所得燒結(jié)坯平均相對密度為95.21%。
關鍵字: NiFe2O4-10NiO/17Ni;金屬陶瓷;惰性陽極;熱脫脂
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;2. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
Abstract:The thermal burnout behavior of PVA was investigated; the failure of the large scale green body occurred in debinder process was mainly conducted by the unstable thermal decomposition of PVA. The new binder system with stable thermal decomposition character was gained and successfully applied in the thermal debinder process of the large scale inert anode samples. The influence of the sintering atmosphere and the addition of Ni on the densification of NiFe2O4-10NiO based ceramic were studied. The results show that N2 atmosphere and the addition of Ni can increase the sintered density of NiFe2O4-10NiO. The relative density of 97.28% for NiFe2O4-10NiO/5Ni is obtained when the samples were sintered at 1 350 ℃ for 2 h in N2 atmosphere. The deep cup shape inert anode sample, with NiFe2O4-10NiO/17Ni and the green dimension of d 120 mm×140 mm, is gained by the optimized process, and its average relative density reaches 95.21%.
Key words: NiFe2O4-10NiO/xNi; cermet; inert anode; thermal debinder


