摘要Mn-Cu系阻尼合金具有较好的力学性能和阻尼性能，为了进一步改善其综合性能将尝试粉末冶金法，将粉末经过球磨、压制成型、烧结、固溶、水淬和时效来制备高阻尼合金。通过X射线衍射仪（XRD）、金相显微镜、横梁振动自由衰减法、维氏硬度计和拉伸机等测试方法，研究了铝成分和烧结温度对Mn79。8Cu19。3Ni4。7Fe2。2合金的阻尼性能和力学性能的变化规律，实验结果表明：用粉末冶金法制备的Mn79。8Cu19。3Ni4。7Fe2。2合金的抗拉强度可以达到400MPa，延伸率达到了14%，与采用熔炼法制备的该合金的力学性能相当。证明采用粉末冶金法可以制备Mn-Cu系阻尼合金是可行的；由于晶界有杂质相析出，容易导致试样开裂，采用起伏式烧结方式可以防止试样开裂；由于Al阻碍了合金化，所以随着Al含量的增加，合金的阻尼性能下降了；由于Al易于吸附气体，使合金的孔隙增加， Al含量越高会降低合金的抗拉强度，塑性也会下降；液相烧结可以填补试样的孔隙，提高了致密度，但使成分发生了偏析，晶粒长大，故而力学性能降低了；试样中的孔隙可以起到减振的效果。87816

毕业论文关键词  阻尼合金  内耗  粉末冶金   孪晶晶界   晶界

 毕业设计外文摘要

Title  The study on preparation,microstructure and properties of Mn-Cu damping alloys。                       

Abstract Mn-Cu damping alloys have good mechanical properties and damping properties 。To improve comprehensive performance of Mn-Cu damping alloys,this project prepare high damping alloys by the means of powder metallurgy that includes ball mill, pressing molding, sintering, water quenching and aging。 In this paper, the changing roles of Mn79。8Cu19。3Ni4。7Fe2。2 alloys’mechanical properties and damping properties in different composition and sintering temperature conditions are studied using X-ray diffractometer Metallographic microscope and free beam vibration attenuation law and vickers hardness tester and drawing machine 。 The results show that: Mn79。8 Cu19。3 Ni4。7 Fe2。2 alloys are prepared by powder metallurgy, their tensile strength can reach 400 MPa and elongation reached 14%, which reached almost the alloy's mechanical properties was prepared by smelting。 So it is feasible that Mn - Cu system damping alloys are prepared by the powder metallurgy。 The liquid phase sintering and then solid phase sintering can prevent the specimen cracking 。 With the increasing of Al, the damping properties of alloy decrease。 Al increase the porosity of alloy because it easily adsorbs gas and Al itself is a soft metal, so the higher Al content will reduce the tensile strength of alloy and decline plastic。 The liquid phase sintering can fill the porosity of the sample and improve the density, but cause the composition segregation and grain growth, so the mechanical properties decreased。 Porosity in a sample can have the effect of vibration damping。源-于,优Y尔E论W文.网wwW.yOueRw.com 原文+QQ752018`766

Keywords  damping alloys,  internal friction,  powder metallurgy,  twin interfaces,  grain boundary

目 次

1  绪论 1

1。1  前言 1

1。2  减振合金的阻尼机制 2

1。3  内耗 的量度和测量方法 4

1。4  制备方法 7

1。5  选题的依据和意义 8

2  材料的制备和试验方法 9

2。1  试验的材料和设备