Al−10Nb−3Ce−2.5B孕育剂对Zn−Al共析合金显微组织、阻尼和拉伸力学性能的影响

Effect of Al−10Nb−3Ce−2.5B inoculant on microstructures,damping and tensile mechanical properties of Zn−Al eutectoid alloy

制备一种新型Al−10Nb−3Ce−2.5B孕育剂,并系统研究其对锌铝共析(ZA22)合金显微组织、阻尼和拉伸力学性能的影响。结果表明,该孕育剂对ZA22合金中的α相具有显著的细化作用(α相最低可被细化至约16μm),并可使得α相的形貌从粗大枝晶状转变为细小花瓣状。通过边−边匹配晶体学模型(E2EM)建立孕育剂中CeB_(6)和NbB_(2)颗粒与α相之间的位向关系(ORs),并基于该E2EM模型揭示孕育剂对ZA22合金的细化机理。与未细化ZA22合金相比,孕育细化ZA22合金的高温阻尼性能,特别是逆共析转变阻尼峰得到显著提升。此外,孕育细化ZA22合金的室温拉伸力学性能也得到了显著提高,具有最佳细化效果的ZA22合金的抗拉强度和伸长率分别比未细化ZA22合金的高18.56%和119.04%。对相关机理进行了讨论。

A novel Al−10Nb−3Ce−2.5B inoculant was prepared,and its effect on microstructures,damping and tensile mechanical properties of Zn−Al eutectoid(ZA22)alloy was systematically studied.It was found that the inoculant had an effective refining effect on theα-phase in the ZA22 alloy(α-phase could be refined to 16μm),and the morphology of theα-phase could also change from coarse dendrite to small petal.Orientation relationships(ORs)between theα-phase and the CeB_(6)and NbB_(2)particles in the inoculant were established by the edge−edge matching model(E2EM),and based on the E2EM,the refining mechanism of the inoculant on the ZA22 alloy was revealed.Compared with the uninoculated ZA22 alloy,the high temperature damping of the inoculated ZA22 alloy,especially the damping peak arising from the reverse eutectoid transformation,was significantly improved.Moreover,the room temperature tensile mechanical properties of the inoculated ZA22 alloy were also significantly improved.The tensile strength and elongation of the ZA22 alloy with the best refining effect were 18.56%and 119.04%higher than those of the unrefined ZA22 alloy,respectively.Correlated mechanisms were discussed.