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以不同钨酸盐前驱体制备的黄钨(YTO)、紫钨(VTO)和细黄钨(AYTO)为原料,在五带控温管式炉中于560~760℃氢还原约300 min获得纳米W粉,通过干磨搅拌配碳将纳米W粉和粉状碳黑粉末混合均匀,然后置于通氢钼丝炉中在1 180℃碳化获得纳米WC粉,并制备了W-30%Cu、WC-30%Cu(质量分数)复合材料烧结体,研究了原料粉末形貌对W、WC粉末的均匀性的影响。通过比表面测定仪和费氏粒度仪测定了粉体的比表面和粒度,用扫描电镜(SEM)观察了粉末的形貌和烧结体的显微组织结构。结果表明,不同形貌的原料制备的纳米W和WC粉末的均匀性不同,钨酸盐(B)制备的细黄钨(AYTO)相成分单一,颗粒细小,具有疏松、多孔形貌结构,以其为原料所获纳米W粉、WC粉末夹粗少,均匀性好,晶粒聚集少。
Hydrogen reduction was carried out at 560 ~ 760 ℃ in five-zone controlled-temperature tube furnace for about 300 min with different tungstate precursors (YTO, VTO and AYTO) as raw materials Nano-W powder, mixed by dry-milling with carbon nano-W powder and powdered carbon black powder mixed evenly, and then placed in hydrogen-molybdenum wire furnace at 180 ℃ carbonized to obtain nano-WC powder and prepared W-30% Cu , WC-30% Cu (mass fraction) composite sintered body, the effect of raw material powder morphology on the uniformity of W and WC powders was studied. The specific surface area and particle size of the powder were measured by BET and Fischer-Tropsch particle size analyzer. The morphology of the powder and the microstructure of the sintered body were observed by scanning electron microscopy (SEM). The results show that the homogeneity of nano-W and WC powders prepared by different morphologies is different. The AYTO phase prepared by tungstate (B) has a single phase with small grains and porous and porous structure. The nano-W powder obtained from the raw material has a small amount of WC powder clip, good uniformity and less aggregation of grains.