(1. 蘭州理工大學(xué) 省部共建有色金屬先進(jìn)加工與再利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050； 2. 蘭州理工大學(xué) 材料科學(xué)與工程學(xué)院，蘭州 730050)
摘 要: 為了研究Ni, Nb, Ta, Ti和Mo元素對(duì)Co-8.8Al-9.8W基合金(摩爾分?jǐn)?shù)，%)顯微組織及γ′相溶解溫度的影響，借助DSC和SEM等方法研究幾種合金元素對(duì)合金γ/γ′兩相顯微組織形貌和γ′相轉(zhuǎn)變溫度的影響。結(jié)果表明：Ni和Mo元素降低γ′相的溶解溫度，而Nb、Ta和 Ti元素提高了γ′相的溶解溫度，且Ta的提高效果最明顯。幾種合金化合金經(jīng)過(900 ℃, 50 h)時(shí)效處理后均形成γ/γ′兩相組織。Ni和Mo元素能使合金中γ′相形貌由立方形變?yōu)榻⒎叫位蚯蛐?如2Ni合金)，而其他合金元素并沒有明顯改變?chǔ)谩湎嗟牧⒎叫蚊病i、Mo與Nb元素使合金中γ′相的體積分?jǐn)?shù)減少，Ni減少的程度較為顯著；但Nb、Ta和Ti元素使γ′相保持較高的體積分?jǐn)?shù)。
關(guān)鍵字: Co-8.8Al-9.8W高溫合金；γ′相；顯微組織；體積分?jǐn)?shù)
（1. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China; 2. School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:In order to study the influences of the Ni, Nb, Ta, Ti and Mo elements on microstructure and solution temperature of Co-8.8Al-9.8W ternary alloy (mole fraction, %), the effects of alloy elements on γ/γ two-phase microstructure and γ′ phase transition temperature were studied by means of DSC and SEM methods. The results show that Ni and Mo elements reduce the melting temperature of γ′ phase, and Nb, Ta and Ti elements improve γ′ phase solution temperature, and the effect of Ta is the most obvious. The γ/γ′ two-phase microstructure of alloys is abserved after aging treatment at 900 ℃ for 50 h. Ni and Mo can make the microstructure of γ′ phase by the cube into nearly cube or spherical (especially 2Ni alloy), and other alloying elements are not significantly change the γ′ cubic phase. Ni, Mo and Nb reduce the volume fractions of γ′ phase, Ni is significant reduction. But alloying additions (Nb,Ta,Ti) keep high volume fraction of γ′ phase.
Key words: Co-8.8Al-9.8W ternary alloy; γ′ phase; microstructure; volume fraction
