草酸盐共沉淀前驱体的热分解过程  

Thermal decomposition process of oxalate coprecipitation precursor

作　　者：黄艳华[1] 谢志刚[1] 贺跃辉[1] 向波[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2007年第1期35-38,共4页Materials Science and Engineering of Powder Metallurgy

基　　金：广西科学研究与技术开发计划资助项目(桂科能05112001-2B1)

摘　　要：研究前驱体热分解过程对制定Ni-Co预合金粉末的制备工艺有一定的指导意义,故采用差热和热重分析法对草酸盐共沉淀前驱体(Ni0.7Co0.3C2O4.2H2O)在氩气和空气中的热分解过程进行研究,并对分解产物进行了物相分析和形貌观察。结果表明:前驱体在这2种气氛下的热分解机制完全相同;分解过程分2步进行,第1步脱去结晶水分子(Ni0.7Co0.3C2O4.2H2O Ni0.7Co0.3C2O4+2H2O↑),第2步无水前驱体分解成Ni-Co合金粉末和CO2;但是,最终的固体产物不同,因为在空气中,生成的Ni-Co合金粉末又与氧气反应,最终得到的固体产物是氧化物(NiO和Co3O4),而在氩气中,最终的固体产物仍然是Ni-Co合金粉末。Investigating precursor＇s thermal decomposition process has certain quiding significance for making out the preparation process of Ni-Co pre-alloyed powders, thereby the thermal decomposition processes of oxalate coprecipitation precursor were studied in argon and air,respectively,by differential thermal and thermogravimetric analyses,and the phases and morphologies of the decomposed products after thermal decomposition were analysed.The results indicated that the mechanism of thermal decomposition in the two different atmospheres is exactly same, i.e.the thermal decomposition takes two steps： firstly, the precursor dehydrated as Ni0.7Co0.3C2O4·2H2O→Ni0.7Co0.3C2O4＋2H2O↑; secondly, the dehydrated precursor decomposed into Ni-Co alloyed powders and CO2. But the ultimate solid products are different： the Ni-Co alloyed powders react with oxygen again, leading the ultimate solid products to be oxide （NiO and C0304 ） in air atmosphere, while the ultimate solid products are still Ni-Co alloyed powders in the argon atmosphere.

关 键 词：前驱体 热分解 差热分析 热重分析 X射线衍射 

分 类 号：TQ138.1[化学工程—无机化工]