(1. 重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400044；
2. 重慶大學(xué) 國家鎂合金材料工程技術(shù)研究中心，重慶 400044；
3. 中國工程物理研究院 總體工程研究所，綿陽 621900)
摘 要: 采用掃描電子顯微鏡、能譜分析儀、X射線衍射儀和動態(tài)機(jī)械熱分析儀等研究Zn含量對Mg-10Gd- 6Y-xZn-0.6Zr(x=0.6, 1.6, 2.6, 3.6，質(zhì)量分?jǐn)?shù)，%)合金顯微組織、力學(xué)和阻尼性能的影響。結(jié)果表明：鑄態(tài)下，Mg-10Gd-6Y-0.6Zn-0.6Zr合金中第二相主要為Mg5(Gd, Y, Zn)，在Mg基體中，由晶界處向晶內(nèi)平行生長出大量層狀相；隨Zn含量的增加，Mg5(Gd, Y, Zn)相減少，Mg12Zn(Y, Gd)相增多；當(dāng)Zn含量達(dá)到3.6%時，第二相主要以Mg12Zn(Y, Gd)相存在，Mg基體中的層狀相幾乎消失。對于擠壓態(tài)的Mg-10Gd-6Y-1.6Zn-0.6Zr合金，其基體中呈現(xiàn)大量扭曲的層狀相，合金抗拉強(qiáng)度達(dá)到400 MPa，隨著Zn含量的增加，合金強(qiáng)度呈下降趨勢，但塑性得到改善。鑄態(tài)合金的阻尼性能隨Zn含量的增加先下降后上升，采用Granato-Lücke(G-L)理論和G-L圖對合金阻尼性能進(jìn)行了分析和討論。
關(guān)鍵字: Mg-Gd-Y-Zn-Zr合金；析出相；力學(xué)性能；阻尼性能；Granato-Lücke理論
（1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China;
3. Institute of System Engineering, China Academy of Engineering Physics, Mianyang 621900, China）
Abstract:SEM, EDS, XRD and DMA (dynamic mechanical analysis) techniques were applied to investigating the effect of Zn content on microstructure, mechanical properties and damping capacities of Mg-10Gd-6Y-xZn-0.6Zr alloys (x=0.6, 1.6, 2.6, 3.6, mass fraction, %). The results show that the major second phase in the as-cast Mg-10Gd-6Y-0.6Zn-0.6Zr alloy is Mg5(Gd, Y, Zn). Besides, a mass of lamellar phases grow parallelly with each other from the grain boundary to the grain interior. With the increase of Zn content, Mg5(Gd, Y, Zn) phase decreases and Mg12Zn(Y, Gd) increases continuously. When the Zn content is 3.6%, Mg12Zn(Y, Gd) exists as the major second phase, and the lamellar phases almost disappear. The numerous distorted lamellar phases precipitate in the grain interior of the as-extruded Mg-10Gd-6Y-1.6Zn-0.6Zr alloy, whose tensile strength reaches 400 MPa. And with the increase of Zn content, the strength of the alloy decreases while the ductility is improved. Finally, the damping capacities of the as-cast Mg-10Gd-6Y-xZn-0.6Zr alloys decrease firstly and increase afterwards, which were analyzed and discussed in terms of the Granato-Lücke (G-L) theories and G-L plots.
Key words: Mg-Gd-Y-Zn-Zr alloy; precipitate; mechanical property; damping capacity; Granato-Lücke theory
