(中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 采用溶膠−噴霧干燥−氫還原法制備稀土Y含量分別為0，0.4%，5%，10%和20%的超細(xì)(W，Ni，F(xiàn)e，Y)復(fù)合粉末，采用XRD研究煅燒溫度和還原溫度以及稀土Y含量變化時(shí)復(fù)合粉末體在制備過程中的相結(jié)構(gòu)變化規(guī)律。結(jié)果表明：噴霧干燥前驅(qū)體隨煅燒溫度的升高漸漸從非晶體向復(fù)合氧化物晶化轉(zhuǎn)變，添加稀土Y的粉末前驅(qū)體經(jīng)煅燒后，Y與W形成復(fù)合氧化物Y2W3O12，且稀土Y可以有效地抑制粉末顆粒長大；隨著Y含量的增加，Y和W的復(fù)合氧化物明顯增加，Y2W3O12在700 ℃才能被還原成低氧復(fù)合氧化物相；含5%稀土Y粉末中的Y2W3O12被還原生成新相Y2WO6；當(dāng)稀土Y增加到10%以上時(shí)，不僅生成Y2WO6，還生成另一種新相Y6W2O15。
關(guān)鍵字: W-Ni-Fe復(fù)合粉末；納米粉末；稀土；Y
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Ultra-fine (W, Ni, Fe, Y) composite powders containing rare earth element Y of 0, 0.4%, 5%, 10% and 20%, respectively were fabricated by sol-spray drying calcination and subsequent hydrogen reduction process. X-ray diffractrometry(XRD) was used to analyze the phase transformation of composite powders during calcination and hydrogen reduction. The results show that the amorphous spray-dried precursors transform into composite-oxide powders, composite oxide phase of Y and W forms as Y2W3O12, and the addition Y can control the grain growth effectively. With the increase of Y contents composite oxide increase obviously. When temperature is 700 ℃, the Y2W3O12 phase is reduced into low-oxygen composite-oxide. A new phase Y2WO6 forms with addition of 5%Y, and when the amount of additions increase up to 10%, the new phases Y2WO6 and Y6W2O15 are formed.
Key words: W-Ni-Fe composite powder; nanopowder; rare earth; Y
