(中南大學 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 采用溶膠−噴霧干燥法制備不同銅含量的W-Cu前驅(qū)體粉末，前驅(qū)體粉末分別在400、600和800 ℃各煅燒90 min，運用XRD和SEM等手段對煅燒前后復合粉末的相組成和顯微形貌進行分析，研究前驅(qū)體粉末在煅燒過程中的相變行為。結(jié)果表明：前驅(qū)體粉末在煅燒過程中發(fā)生一系列的分解和化合反應，隨著煅燒溫度的升高，粉末的相組成、顆粒形貌和尺寸發(fā)生明顯變化，對W-30%Cu(質(zhì)量分數(shù))合金，在400 ℃煅燒后，復合粉末由WO3、CuO和CuWO4組成，粉末顆粒大多呈立方結(jié)構，大小為200~400 nm；在600 ℃煅燒后，復合粉末由CuO和CuWO4組成，粉末顆粒大多呈短棒狀結(jié)構，大小為400~500 nm；在800 ℃煅燒后，復合粉末由CuO、CuWO4和Cu3WO6組成，粉末顆粒大小為3~4 μm；前驅(qū)體粉末中銅含量對煅燒后復合粉末的相組成也存在較大影響，銅含量越多，越容易生成復合氧化物。
關鍵字: W-Cu；CuWO4；Cu3WO6；高溫煅燒；相變；溶膠−噴霧干燥
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:W-Cu precursor powders with different copper contents were fabricated by sol-spray drying. Precursor powders were calcined at 400, 600 and 800 ℃ for 90 min, respectively. Phases and microstructure of pre-calcined and post-calcined powders were investigated by XRD and SEM in order to study the phase transformation of precursor powders. The results show that precursor powders undertake a series of decomposing and compounding reactions during calcining. With the increasing of calcining temperature, the phases, morphology as well as particle size of the powder change obviously. For W-30%Cu (mass fraction) composite powder, the composite powder is composed of WO3, CuO and CuWO4 after calcining at 400 ℃ and the particles exhibit cubic shape with sizes of 200−400 nm. The powder after calcining at 600 ℃ consists of CuO and CuWO4 and the particles are mostly of rod-like shape of 400−500 nm in size. The powder after calcining at 800 ℃ is composed of CuO, CuWO4 and Cu3WO6 phases and the particles are 3−4 μm in size. The copper content in the precursor powder greatly influence the phase composition of the calcined powders. The increase of copper content facilitates the formation of composite oxide.
Key words: W-Cu; CuWO4; Cu3WO6; high temperature calcine; phase transformation; sol-spray drying
