【正文】 nodal structures and twinning structures. Spinodal structures strengthen alloy by the coherent stress field between the separated phases. Twinning boundaries act as a barrier of dislocations and result in the increase of strength. Deformations result in the dramatic decrease of damping capacity of Mn20Cu 5Ni2Fe alloy. The damping capacity decreases with the increment of deformations, and the damping capacity is much lower when the deformation rate is higher than 2%. The decrease of damping capacity is mainly attributed to the formation of dislocations when the deformations are applied, which retard the slip of twinning boundaries. Retreatment (aging at 435℃ ) can make stress field of dislocations disappeared fully or partly, and thus the damping capacity can be restored fully or partly after retreatment. When deformation rate is small, the twinning structures 四川大學(xué)碩士學(xué)位論文 V bee nicked and rearrangement, and at this case the damping capacity can be restored pletely. While when the deformation rate is relatively higher, the twinning structures are changed dramatically and thus the damping capacity only can be restored partly. Keywords: MnCu damping alloy。當(dāng)形變量較小時孿晶帶變細(xì)并發(fā)生重排，此時回復(fù)處理能使合金阻尼性能完全回復(fù)；隨著形變增加，孿晶結(jié)構(gòu)遭到破壞，回復(fù)處理只能使合金的阻尼性能得到部分回復(fù)。 形變會使 Mn20Cu5Ni2Fe 合金阻尼性能顯著降低。 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(yīng)降低。在 400~500℃保溫， MnCu 合金會發(fā)生 調(diào)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(guān)，時效溫度升高該含量降低。在時效時間為 4h 時，合金在 435℃達(dá)到最大阻尼性能（ δ=）。從材料的組織和性能之間的關(guān)系出發(fā)，主要探討了以下三個方面的內(nèi)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(xué)性能的影響； 形變熱處理對 Mn20Cu5Ni2Fe 合金阻尼性能的影響。四川大學(xué)碩士學(xué)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(dǎo)教師 李 寧教授 隨著現(xiàn)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(lǐng)域得到了越來越廣泛的應(yīng)用。通過分析得到了如下結(jié)論： 合金阻尼性能對時效溫度和時效時間敏感。時效溫度越高，合金達(dá)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。四川大學(xué)碩士學(xué)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(zhuǎn)變和fccfct 轉(zhuǎn)變。 合金強度隨時效時間的增加可分為兩個階段，當(dāng)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。合金阻尼性能隨形變量的增加而迅速降低，當(dāng)形變量大于 2%時，合金的阻尼性能已顯著降低。 關(guān)鍵詞： MnCu阻尼合金； 時效； 孿晶界面；調(diào)幅分解； fccfct 轉(zhuǎn)變；形變及回復(fù) 四川大學(xué)碩士學(xué)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。 aging treatment。 deformation and retreatment. 四川大學(xué)碩士學(xué)位論文 VI 目錄 熱處理工藝對 Mn20Cu5Ni2Fe 阻尼合金組織和性能的影響 .............................. I Effect of heat treatment on microstructures and properties in Mn20Cu5Ni2Fe damping alloy .............................................................................................................III 目錄 ........................................................................................................................... VI 第 1 章 緒論 ............................................................................................................... 1 阻尼合金的特點及分類 .............................................................................. 1 內(nèi)耗 ................................................................................................... 1 阻尼合金的分類 ............................................................................... 2 合金阻尼性能的表征及測試方法 .............................................................. 4 阻尼性能的表征 ............................................................................... 4 阻尼性能測試方法 ........................................................................... 7 MnCu高阻尼合金國內(nèi)外研究現(xiàn)狀 .......................................................... 9 MnCu 合金的相變 ............................................................................. 9 MnCu 合金的內(nèi)耗特征 ................................................................... 12 合金化 ............................................................................................. 13 熱處理 ............................................................................................. 15 形變對阻尼性能的影響 ................................................................. 16 MnCu 合金的工程應(yīng)用 .............................................................................. 17 選題意義及研究內(nèi)容 ................................................................................ 18 選題意義 ......................................................................................... 18 本文研究內(nèi)容 ................................................................................. 18 本文技術(shù)路線 ................................................................................. 20 第 2 章 實驗材料及方法 ......................................................................................... 21 實驗材料 .................................................................................................... 21 實驗方法 .................................................................................................... 21 熱處理方法 ..................................................................................... 21 阻尼性能測試 ...............................