超细Co-Cr-V复合金属粉末的制备与表征  

Preparation and characterization of ultrafine Co-Cr-V alloy powders

作　　者：陈晓宇[1] 李詠侠 邹丹 刘艳军 谢元彦 刘宇尘[1] 姚锐[1] 廖松义 郑峰[1,3] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]湖南博云东方粉末冶金有限公司,湖南长沙410205 [3]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2017年第2期302-309,共8页Journal of Central South University:Science and Technology

基　　金：国家高技术研究发展计划(863计划)项目(2013AA032001);中南大学粉末冶金国家重点实验室开放研究课题~~

摘　　要：利用共沉淀-热分解法,制备出超细复合碱式碳酸盐前驱体和Co-Cr-V复合金属粉末。利用X线衍射仪和红外吸收光谱分析前驱体和复合金属粉末的物相与晶体结构,用电感耦合等离子体原子发射光谱测定复合金属粉末的元素组成和含量。研究结果表明:前驱体为单相碱式碳酸钴,煅烧得到包含α-Co(fcc)和β-Co(hcp)的两相Co-Cr-V复合金属粉末,其中α-Co相含量在pH为11时达到最大值,约为82%(质量分数)。通过DSC-TG(氩气气氛)分析,研究前驱体的热分解行为,发现前驱体的热分解过程与碱式碳酸钴相似,大约在259和951℃分别发生一次和二次离解。利用扫描电镜观察前驱体和复合金属粉末的形貌,发现煅烧后的复合金属粉末与前驱体的形貌相似,具有继承性,均为类球状颗粒团聚体。利用比表面积分析仪测定前驱体与复合金属粉末的比表面积,并据此估算出粉末的平均粒度:前驱体的粒度在5~11 nm之间,煅烧后得到的复合金属粉末粒度显著增大,接近或达到亚微米级;复合金属粉末粒度随pH(pH在7~11之间)增大而增大,当pH为7时,粉末的平均粒度约为96 nm。Ultrafine complex basic cobalt carbonate and Co-Cr-V alloy powders were prepared by co-precipitation and thermal decomposition method. X-ray diffraction（XRD） and infrared spectroscopy（IR） were used to analyze phase and crystal structure of as-synthesized powders, and inductively coupled plasma atomic emission spectrometer（ICP-AES）was used to determine element composition and content of alloy powders. The results show that the precursor can be indexed to pure phase of basic cobalt carbonate while alloyed powders consist of two cobalt phases corresponding toα-Co（fcc） and β-Co（hcp） respectively. The maximum content of α-Co reaches 82%（mass fraction） at p H=11. Combined the analysis of thermogravimetry-differential scanning calorimetry（TG-DSC）, precursor powders were conducted in flowing argon with two characteristic peaks occurring at 259 and 951 ℃ associated to decomposition of basic cobalt carbonate. Scanning electron microscopy（SEM） was employed to observe the morphology change of as-synthesized powders and alloy powders. Specific surface area analyzer was used to determine the specific surface area of precursor and alloy powders. The precursor powders is extremely fine with average particle size ranged from 5~11 nm. The average particle size of alloy powders is much larger and in sub-micrometer range. The average particle size is a linear function of pH with the smallest partice size of 96 nm observed at pH=7.

关 键 词：共沉淀-热分解法 超细粉末 置换固溶体 类球状 

分 类 号：TB383[一般工业技术—材料科学与工程]