(西安理工大學(xué) 陜西省電工材料及熔滲技術(shù)重點(diǎn)實(shí)驗(yàn)室，西安 710048)
摘 要: 采用機(jī)械合金化法制備Cr含量為8%、12.5%、20%(質(zhì)量分?jǐn)?shù))的納米W-Cr合金粉，對(duì)不同球磨時(shí)間粉末進(jìn)行X射線衍射分析，以確定物相、晶粒尺寸及微應(yīng)變，并采用掃描電子顯微鏡觀察粉末形貌及粒度的變化。結(jié)果表明，采用機(jī)械合金化法可以制備不同Cr含量的納米W-Cr合金粉。隨著Cr含量的增加，制備納米W-Cr合金粉所需球磨時(shí)間越長，其中W-8%Cr、W-12.5%Cr和W-20%Cr粉末的最佳球磨時(shí)間分別為72、84和96 h，晶粒尺寸小于30 nm。隨著球磨時(shí)間的增加，晶粒尺寸不斷減小，微應(yīng)變逐漸增加，使常溫下Cr在W中的固溶度增加，形成W的過飽和固溶體。Cr含量不同的W-Cr粉末完全合金化均經(jīng)過4個(gè)階段。
關(guān)鍵字: WCr合金粉末；機(jī)械合金化；Cr含量
（Shaanxi Key Laboratory of Electrical Materials and Infiltration Technology, Xi’an University of Technology, Xi’an 710048, China）
Abstract:Abstract: The W-Cr nano alloying powders with the composition of W-8%Cr, W-12.5%Cr and W-20%Cr (mass fraction) were prepared by mechanical alloying. The phase structure, grain size and micro-strain of the powders were determined using X-ray diffractometry. The morphology and particle size of the powders were observed and analyzed by scanning electron microscopy. The results show that the W-Cr nano alloying powders can be obtained by mechanical alloying. With the increase of Cr content, the ball milling time should be prolonged in order to get W-Cr alloying powders. The optimum time of ball milling for W-8%Cr, W-12.5%Cr and W-20%Cr powders is 72, 84 and 96 h, respectively. Grain size of the powders is less than 30 nm. With the time of ball milling increasing, the particle size becomes smaller; the extent of micro-strain and distortion of lattice are intensified; and the solution limitation of Cr in W is enlarged. The super-saturated solid solution of W is obtained finally. Although the content of Cr and the time of ball milling are different, the change of W-Cr alloying powders undergoes four stages.
Key words: W-Cr alloying powders; mechanical alloying; Cr content
