宏观孔对金属材料阻尼行为的影响及其阻尼机制研究  

Study on the Influence of Macroscopic Pores on the Damping Properties of Metal Materials and Damping Mechanisms

作　　者：魏健宁[1] 李根梅[2] 侯翠岭[1] 周利玲[1] 

机构地区：[1]九江学院理学院,九江332005 [2]九江学院机械与材料工程学院,九江332005

出　　处：《材料导报》2015年第10期86-88,93,共4页Materials Reports

基　　金：江西省教育厅科研项目(GJJ13731;GJJ11240;GJJ11239)

摘　　要：采用空气加压渗流技术制备了含宏观孔开孔泡沫金属材料,运用内耗技术研究了宏观孔对金属材料阻尼行为的影响及其阻尼机制,宏观孔的引入大大提高了材料的阻尼性能。泡沫金属材料的基体为工业纯铝和锌铝共析合金,宏观孔的平均直径约0.5mm和1.4mm,宏观孔孔隙率为69%和65%。在多功能内耗仪上采用连续变温受迫振动方式测量了泡沫金属材料的内耗和相对动力学模量。实验表明泡沫金属材料的阻尼能力随着宏观孔的减小、宏观孔孔隙率的增加而增加,依据实验结果提出了泡沫金属可能的阻尼机制:晶界阻尼、位错阻尼、孔周围的应力集中和模式转换、孔洞/金属基体界面处由于动力学模量相差很大而使机械能转化为热能和孔洞发生不均匀膨胀或畸变使外加应变能耗散为热能。The foamed metal materials with macroscopic open pores were prepared by air pressure infiltration process. The effects of macroscopic pores on the damping behavior of metal materials were systematically studied. The metal matrix of the foamed metal materials were commercially pure Aluminum and Zn-A1 eutectoid alloy, whose mean diameters of the macroscopic pores were 0. 5 mm and 1.4 ram, and porosities were 69% and 65%, respectively. The damping characterization was conducted on a multifunction internal friction apparatus （MFIFA） through forced vibra- tion. The internal friction （IF）, as well as the relative dynamic modulus, were measured at different frequencies over the temperature range. The damping capacity of the foamed metal materials is shown to increase with increasing porosi- ty and decreasing macropore size. In light of IF measurements, the possible operative damping mechanisms in the foamed metal materials are. grain boundary, dislocation, the stress concentration and mode conversion around macro- scopic pores, the elastic modulus difference between the matrix and the macroscopic pores that results in a marked in- homogeneous stress, inhomogeneous expansion deformation around macroscopic pores.

关 键 词：泡沫金属 内耗 宏观孔 

分 类 号：TB331[一般工业技术—材料科学与工程]