纳米晶复合碳化钨-钴粉末的工业化制备技术

Commercial Production Technique for Nanocrystalline Composite Powder of WC-Co

超细晶粒的WC-Co硬质合金具有高硬度、高强度的性能,纳米晶WC-Co复合粉末的合成是制备该合金的首要前提工作,中国正努力保持和强化“钨钴液相复合—喷雾干燥—流态化连续还原碳化技木”在国际上的前沿优势。该技术将偏钨酸铵和水合硝酸钴以分子级水平混合,经喷雾干燥制备出CoWO_4/WO_3复合氧化物前驱体粉末,然后将前驱体粉末置于流态化反应炉中,在H_2/CH_4/CO_2/N_2气氛下经过连续的还原、碳化、调碳过程,得到无缺碳相的纳米晶WC-Co复合粉末。

Ultrafme grained WC-Co cermet has high hardness and high strength- Preparing nanocrystallmeWC-Co composite powder is one of the most important processes in the manufacture of the cermet. Currently Chinese researchers are leading the world in the area with their 'W/Co solution mixing-dry spraying-continuous fhudized re-duction/carburization ' technology. In this study, the precursor powder was prepared by mixing ammonium metatungstate and cobalt nitrate at the molecular level in distilled water and then spray-dried to form CoWO1/WO3 composite oxides. Through continuous reduction/carburization gas-solid reaction in a fluidized bed reactor in H2/CH4/ CO-/N2, the precursor was converted to WC-Co nanocrystallme composite powder.