Al-Zn合金阻尼机制以及阻尼性能影响因素

发布时间：2018-04-19 00:32

本文选题：铝锌合金 + 阻尼性能　；参考：《西南交通大学》2017年硕士论文

【摘要】：锌铝基合金因其优异的机械性能、耐磨性、阻尼性能及低廉的成本,被广泛应用于替代传统材料生产轴承、轴瓦、滑块等部件。大多数国内外学者的研究多集中在Zn含量高于50wt.%的锌铝合金,而对于Zn含量低于50wt.%的铝锌合金研究较少。铝锌合金与锌铝合金相比由于Zn含量低,具有质量轻的优势且具有一定阻尼性能。为更多更好地了解铝锌合金,本文对铝锌合金进行了研究。本课题为确定合适的合金成分,以获得阻尼性能优异、力学性能良好的轻量化铝锌合金,分别熔炼了 Al-25wt.%Zn,Al-35wt.%Zn和Al-45wt.%Zn三种成分的铝锌合金并进行了均匀化热处理,通过优化选取Al-45wt.%Zn,并向Al-45wt.%Zn合金中分别加入了 0.4wt.%,0.6wt.%,0.8wt.%的Ti和Zr,再次选定最优成分后又分别进行了 380℃×3h+400℃×1h,370℃×10h+180℃×6h,350℃×2h+200℃×1Oh 的热处理实验。通过金相显微观察、X-射线衍射、阻尼性能测试、室温拉伸试验、显微硬度测试对试样进行了组织性能对比,得到的研究成结果如下:(1)在本文研究的二元合金中,Zn含量的越多,合金的阻尼性能越好。Al-45wt.%Zn合金的晶粒最细,共析强化相最多,使得可动界面的数量最多,因此,Al-45wt.%Zn合金表现出性能最优,其阻尼值为0.012,分别比Al-25wt.%Zn和Al-35wt.%Zn合金的阻尼值提高了 50%和16.7%。抗拉强度为243.1MPa,屈服强度为198.8MPa,伸长率为3.7%,硬度为 85.9HV。(2)(Al-45wt.%Zn)-0.6wt.%Ti 和(Al-45wt.%Zn)-0.6wt.%Zr 的阻尼性能最优,阻尼值分别为0.014和0.013。相比于二元Al-45wt.%Zn合金阻尼值分别提高了 16.7%和8.3%,加入0.4wt.%Ti和0.4wt.%Zr可以细化晶粒;加入0.6wt.%Ti和0.6wt.%Zr能与A1生成金属间化合物,作为异质形核的核心,弥散强化,增加晶界。加入0.6wt.%Ti的铸态合金的硬度值为94.6HV、比二元合金提高了 10.1%,但低于加入0.8wt.%Ti的铸态合金,其硬度值101.3HV;加入0.6wt.%Zr的硬度最强,为96.2HV,比二元合金提高了 12%。一方面晶粒的细化可以增强合金的硬度,另一方面过量的金属间化合物会析出在晶界,阻碍晶界的可动性,对硬度有贡献作用。(3)热处理 350℃×2h+200℃×1Oh 对(Al-45wt.%Zn)-0.6wt.%Ti,370℃×10h+180℃×6h对(Al-45wt.%Zn)-0.6wt.%Zr三元铸态阻尼性能改善效果最好,阻尼值分别达到了 0.0175和0.018,相比于Al-45wt.%Zn二元合金分别提高了 45.8wt.%和50%,相比于(Al-45wt.%Zn)-0.6wt.%Ti 和(Al-45wt.%Zn)-0.6wt.%Zr 三元铸态合金分别提高了25%和38.5wt.%;抗拉强度分别为214.2MPa和222.4MPa,屈服强度分别为209.8MPa和214.3MPa,与二元合金相差不大;拉伸率分别为16.1wt.%和15.9%,相比于二元Al-45wt.%Zn合金分别提高了 335%和330wt.%;硬度分别为128.7HV和113.7HV,相比于二元 Al-45wt.%Zn 合金分别提高了 49.8%和 32.4wt.%,相较于(Al-45wt.%Zn)-0.6wt.%Ti 和(Al-45wt.%Zn)-0.6wt.%Zr 三元铸态合金分别提高了 36wt.%和 18.2wt.%,综合性能最好。热处理提高阻尼性能的原因是温度升高,加热时间增长,一些铸态时的非平衡相分解,成分趋于均匀化,层片状共析相逐渐转变为粒状,将共格界面转变为非共格界面,晶粒细化,阻尼性能增强。晶界中的低熔点共晶物溶解,界面可动性增强,阻尼性能提高的同时塑性增强,强度降低;η硬相增多,强度增大。
[Abstract]:The zinc aluminum alloy because of its excellent mechanical properties, abrasion resistance, damping performance and low cost, is widely used in the production of traditional materials instead of bearings, bearing, slide and other components. Most of the research scholars at home and abroad are more concentrated in the Zn Aluminum Alloy zinc content is higher than 50wt.%, and for Zn was lower than that of aluminum zinc alloy study of 50wt.%. Aluminum zinc alloy and zinc Aluminum Alloy compared due to the low content of Zn has the advantages of light weight and has certain damping properties. For more and better understanding of aluminum zinc alloy, this paper studied the aluminum zinc alloy. This subject is sure to obtain suitable alloy composition, excellent damping performance, light quantification of Al Zn alloy with good mechanical properties of Al-25wt.%Zn, Al-35wt.%Zn and Al-45wt.%Zn were melting, three components of aluminum zinc alloy and the homogenization heat treatment, Al-45wt.%Zn is selected through optimization, and to the Al-45wt.%Zn alloy Add to 0.4wt.% 0.6wt.%, 0.8wt.%, Ti and Zr, and then again to select the optimal components were 380 DEG C C * 3h+400 * 1H, 10h+180 * 6h * 370 DEG C, the heat treatment experiment 350 c * 2h+200 * C 1Oh. Through metallographic observation, X- ray diffraction, damping performance test, room temperature tensile test, microhardness test of the organizational performance comparison on the sample, the research results are as follows: (1) in the two alloys in this study, the content of Zn increasing, the grain better damping properties of.Al-45wt.%Zn alloy alloy of the finest, most eutectoid strengthening phase, so that the number of the most moving interface, so Al-45wt.%Zn, the alloy exhibits the best performance, the damping value is 0.012, respectively Al-25wt.%Zn and Al-35wt.%Zn alloy damping values increased by 50% and 16.7%. 243.1MPa for the tensile strength, yield strength is 198.8MPa, elongation is 3.7%, the hardness is 85.9HV. (2) (Al- 45wt.%Zn) and -0.6wt.%Ti (Al-45wt.%Zn) -0.6wt.%Zr optimal damping properties, damping values were 0.014 and two yuan 0.013. compared to Al-45wt.%Zn alloy damping values were increased by 16.7% and 8.3%, adding 0.4wt.%Ti and 0.4wt.%Zr can refine grain; adding 0.6wt.%Ti and 0.6wt.%Zr to form intermetallics and A1 as heterogeneous nucleation core, dispersion strengthening increase, join the 0.6wt.%Ti grain boundaries. The hardness of the alloy is 94.6HV, 10.1% higher than two yuan but less than that of 0.8wt.%Ti alloy, joined the cast alloy, the hardness of 101.3HV value; adding 0.6wt. hardness of%Zr is 96.2HV, the strongest, two yuan more than the alloy improves hand grain refinement of 12%. alloy can be enhanced the hardness, on the other hand excessive intermetallic compounds will be precipitated at the grain boundary, grain boundary mobility hinder, contribute to the hardness. (3) heat treatment at a temperature of 350 DEG C * 2h+ * 1Oh (Al-45 to 200 DEG C Wt.%Zn -0.6wt.%Ti, 370 10h+180) C + C + 6h (Al-45wt.%Zn) -0.6wt.%Zr of three yuan cast the best damping capacity improvement effect, the damping value reached 0.0175 and 0.018, compared to two yuan Al-45wt.%Zn alloy were increased by 45.8wt.% and 50%, compared to the (Al-45wt.%Zn) -0.6wt.%Ti and -0.6wt.%Zr (Al-45wt.%Zn) three yuan cast alloy were increased by 25% and 38.5wt.%; 214.2MPa and 222.4MPa respectively, the tensile strength, yield strength were 209.8MPa and 214.3MPa, and the two element alloy difference; the stretching rate was 16.1wt.% and 15.9% respectively, compared to two yuan Al-45wt.%Zn alloy were increased by 335% and 330wt.%; the hardness of 128.7HV and 113.7HV, compared to two yuan Al-45wt.%Zn alloy were increased by 49.8% and 32.4wt.%, compared to the (Al-45wt.%Zn) -0.6wt.%Ti and -0.6wt.%Zr (Al-45wt.%Zn) three yuan cast alloy are increased by 36wt.% and 18.2wt.%, comprehensive The best performance. To improve the damping performance of the heat treatment temperature increased, the heating time increases, some cast the non-equilibrium phase decomposition, composition uniformity, lamellar eutectoid phase gradually transformed into granular, the coherent interface into non coherent interface, grain refinement, enhance the damping performance of the grain boundary. Low melting point eutectic dissolved, the interface mobility enhancement, damping performance improves increased plasticity and strength reduction; ETA hard phase increase, the strength increased.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG146.21

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