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...................... 43 微觀結構對阻尼性能的影響 ......................................................... 45 微觀組織對合金力學性能的影響 ................................................. 48 小結 ............................................................................................................ 50 第 4 章 形變及回復處理對 Mn20Cu5Ni2Fe 阻尼性能的影響 ......................... 51 引言 ............................................................................................................ 51 實驗結果 .................................................................................................... 51 形變對 Mn20Cu5Ni2Fe 合金阻尼性能的影響 ......................... 51 回復處理對 Mn20Cu5Ni2Fe 合金阻尼性能的影響 ................. 52 形變及回復處理對微觀組織的影響 ............................................. 53 分析與討論 ..................................................................................... 55 小結 ............................................................................................................ 56 第 5 章 結論 ............................................................................................................. 57 參考文獻 ................................................................................................................... 59 研究生在讀期間科研成果簡介 ............................................................................... 64 聲明 ........................................................................................................................... 65 致謝 ........................................................................................................................... 66 四川大學碩士學位論文 1 第 1章 緒論 隨著現代科技工業(yè)的高速發(fā)展,各種機械設備的運轉功率及效率不斷提高,但伴隨而來的振動、噪聲等問題也越來越突出。 spinodal deposition。 aging treatment。 3, the effects of thermomechanical treatment on damping properties in Mn73Cu20 Ni5Fe5 alloy. From these studies, we can conclude that: The damping capacity of Mn20Cu5Ni2Fe alloy is sensitive to aging temperature and time. The spinodal deposition temperature of Mn20Cu5Ni 2Fe alloy ranges from 400℃ to 500℃ . When Mn20Cu5Ni2Fe alloy is aged for 四川大學碩士學位論文 IV 4h, the damping capacity of alloy shows a parabolic relationship with aging temperature, and at this time peak damping capacity (δ=) is obtained at 435℃ . With a higher aging temperature, a shorter aging time was used to reach damping peak, but a lower peak damping capacity was obtained. With increasing aging time, damping capacity first increase and then decrease. The damping capacity of MnCu alloy originates from the slip of twinning structures, while the twinning structures are attributed to the spinodal deposition of MnCu alloy. Spinodal deposition occurred, which lead to the formation of Mnrich region, when MnCu alloy was aged at 400~500℃ . With increasing aging time, Mnrich regions grow and the phase transformation points increase, which result in antiferromagic transformation and fccfct transformation. According to the strain release mechanism, lattice is changed and twinning structures are formed. When MnCu alloy is overaged, dislocations are formed between twinning boundaries and result in decrement of damping capacity. The strength and hardness increase with aging temperature and aging time, and elongation decrease correspondingly. Strength behavior with increment of aging time can be divided into two stages: I) the strength increases rapidly when aging time is shorter than 4h。 關鍵詞: MnCu阻尼合金; 時效; 孿晶界面;調幅分解; fccfct 轉變;形變及回復 四川大學碩士學位論文 III Effect of heat treatment on microstructures and properties in Mn20Cu5Ni2Fe damping alloy Major: Materials Processing Engineering Postgraduate: Fu Xu Supervisor: Prof. Li Ning With the rapid development of modern industries and the pursuit of high quality of life, reducing vibration and noise has bee an important issue that must to be solved. Damping materials, because of its unique properties of vibration reducing, have been widely used in reducing vibration and noise. MnCu alloy, a twinning type of high damping materials, shows a bination of good strength and high damping capacity and has attracted extensive attention. In the present paper, JN1 inverse torsion pendulum, optical microscope, XRay diffraction (XRD) and transmission electron microscope (TEM) were carried out to study for the relationship between microstructures and properties in Mn73Cu20 Ni5Fe5 alloy. We considered three aspects: 1, the effects of aging treatment on damping properties in Mn20Cu5Ni2Fe alloy。形變后在 435℃保溫會使位錯應力場消失或部分消失從而使 形變后的合金阻尼性能得到一定程度的回復。合金阻尼性能隨形變量的增加而迅速降低,當形變量大于 2%時,合金的阻尼性能已顯著降低。調幅組織通過兩相區(qū)共格應力場而使合金得到強化;孿晶界面對位錯的滑移有阻礙作用,因此孿晶密度升高也會使合金的力學性能升高。 合金強度隨時效時間的增加可分為兩個階段,當時效時間小于 4h時,合金的 強度迅速上升,而時效時間繼續(xù)增加,強度增加的幅度降低。合金過時效會在孿晶界面形成位錯網絡阻礙孿晶界面的滑移,因此阻尼性能降低。四川大學碩士學位論文 II 富 Mn 區(qū)的形成使合金的相變點升高,在冷卻至室溫過程中發(fā)生反鐵磁轉變和fccfct 轉變。 孿晶結構是 MnCu 合金具有高阻尼性能的原因,而調幅分解是導致 MnCu合金產生孿晶結構的前提。時效溫度越高,合金達到阻尼峰值的時間就越短,但此時合金的阻尼峰值反而降低。在不同溫度下時效 4h 后,阻尼性能與時效溫度較好的滿足拋物線關系。通過分析得到了如下結論: 合金阻尼性能對時效溫度和時效時間敏感。本文采用 JN1型倒扭擺儀、光學顯微鏡、 XRD 和 TEM 等測試分析方法研究了熱處理工藝對Mn20Cu5Ni2Fe 合金組織和性能的影響。四川大學碩士學位論文 I 熱處理工藝對 Mn20Cu5Ni2Fe 阻尼合金 組織和性能的影響 材料加工工程專業(yè) 研究生 傅 旭 指導教師 李 寧教授 隨著現代科技工業(yè)的高速發(fā)展,以及人類對生活環(huán)境要求的不斷提高,減振降噪成為亟待解決的問題,而阻尼合金由于其獨特性能在減振降噪領域得到了越來越廣泛的應用。 MnCu 合金屬于孿晶型高阻尼合金,該合金兼具了較高的力學性能和阻尼性能,因此得到了國內外學者的廣泛關注。從材料的組織和性能之間的關系出發(fā),主要探討了以下三個方面的內容: 時效處理對 Mn20Cu5Ni2Fe 合金阻尼性能的影響; 時效處理對 Mn20Cu5Ni2Fe 合金力學性能的影響; 形變熱處理對 Mn20Cu5Ni2Fe 合金阻尼性能的影響。 Mn20Cu5Ni2Fe 合金獲得阻尼性能的溫度區(qū)間為 400℃ ~500℃。在時效時間為 4h 時,合金在 435℃達到最大阻尼性能( δ=)。隨時效時間的增加,阻尼性能先增加然后又緩慢降低。在 400~500℃保溫, MnCu 合金會發(fā)生 調幅分解,該分解使低 Mn 含量的 MnCu 合金形成富 Mn 區(qū),隨著時效時間的增加,富 Mn區(qū)長大,富 Mn 區(qū)的最大 Mn 含量與時效溫度有關,時效溫度升高該含量降低。通過應變釋放機制,晶格發(fā)生一定程度的畸變,形成孿晶結構。 合金的 強度和硬度隨時效溫度的升高和時效時間的增加而升高,而延伸率相應降低。孿晶結構和調幅組織是 Mn20Cu5Ni2Fe 合金力學性能變化的原因。 形變會使 Mn20Cu