(1. 西安理工大學(xué)機(jī)械與精密儀器工程學(xué)院, 西安 710048;
2. 西北工業(yè)大學(xué)凝固技術(shù)國家重點實驗室, 西安 710072)
摘 要: 研究了過飽和ZAC27合金在自然時效過程中的組織演變與其阻尼性能的關(guān)系。過飽和ZAC27合金時效1 d后，組織中出現(xiàn)了大量的η 相、α相和少量 的ε相。 隨時效時間的延長 ，η相、α相和ε相的量越來越多，時效10 d后，β相已分 解完全并消失。 此后各相進(jìn)一步粒化、聚集，在50 d后形成了較粗大的、由近似等軸的短棒狀的α相、η相和ε 相組成的平衡組織。過飽和ZAC27合金在自然時效過程初期， 阻尼性能迅速而明顯地提高，在時效第10d時聲頻阻尼性能達(dá)到最高值，約為7×10-3 ；隨后阻尼性能緩慢下降,50 d后基本穩(wěn)定不變, 穩(wěn)定后的阻尼性能約為4×10-3。過飽和Z AC27合金的阻尼來 源于界面阻尼和位錯阻尼，η相和ε相從過飽和ZAC27合金中的脫溶以及溶質(zhì)原子 和淬火空位 與位錯的交互作用是過飽和ZAC27合金阻尼性能產(chǎn)生變化和提高的主要原因。 ZAC27合金均 勻化熱處理及自然時效是一種很好的提高阻尼性能的熱處理工藝。
關(guān)鍵字: ZAC27合金； 組織演變； 阻尼性能
（1. School of Mechanical and Instrumental Engineering, Xi′an University of Technology, Xi′an 710048, P.R.China；
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi′an 710072, P.R.China）
Abstract:The microstructural evolution of supersa turated ZAC27 alloy and its damp ing capacities were investigated systematically in the period of natural ageing. The investigation shows that the microstructure of ZAC27 alloy evolves as follo ws: after 1 day ageing, α phase, η phase and ε phase appear in the alloy， moreo ver, the amount of α phase, η phase and ε phase increase with th e increasing of ageing time; after 10 d ageing, the β phase decomposes and vanishes completely in the alloy； after 50 d ageing, phases gather and form the coarser equil ibrium microstructure which consists of near equiaxed, shot clubshaped α, η and ε phase. Microstructure changes accompany with the variance of dampi ng ca pacity. It is found that the damping capacities varies quickly and obviously du ring natural ageing. The damping capacity reaches the highest value 7×10-3 at th e 10th day. Sequentially, the damping capacity decreases gradually, and reaches a constant value of 4×10-3 after 50d natural ageing. The dampi ng behavior in supersaturated ZAC27 alloy comes from a superposition of two mechanisms: inte rface damping and dislocation damping. The reasons for the great change of dam ping capacity of supersaturated ZAC27 alloy are as follows: 1) the pr ecipitation of η and ε phases from supersaturated β solid solution and 2) the i nteraction of di slocation with vacancies and solute atoms. The results also indicate that solid solution+water quenching+natural ageing is the best heat treatment technique to improve the damping capacity of the ZAC27 alloy substantially.
Key words: ZAC27 alloy; microstructural evolution; da mping capacity
