(西北工業(yè)大學(xué)凝固技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室, 西安 710072)
摘 要: 研究了鋁、銅、鎂等合金化元素對(duì)鑄態(tài)鋅基合金組織和室溫下阻尼性能的影響，利用懸臂梁法測(cè)試了合金的阻尼性能。結(jié)果表明，鋅鋁二元合金隨鋁含量增加，初生α相增多，共晶體逐漸減少直至消失。鎂、銅等合金元素對(duì)Zn-27%Al合金α相的大小和分布無(wú)大的影響。鎂、銅可固溶于基體中，當(dāng)其含量較高時(shí)，分別在組織中形成MgZn2化合物和CuZn5化合物，分布于晶界。鋁含量在6%～60%范圍內(nèi)的鋅鋁合金在鑄態(tài)下均具有高的阻尼能力；銅、鎂等合金化元素的加入降低了Zn-27%Al合金的阻尼性能。Zn-Al系合金的高的阻尼性能是在外部的交變應(yīng)力作用下，晶界和相界間的粘滯性滑動(dòng)以及α相發(fā)生局部的微塑性變形，使振動(dòng)能量得以消耗而造成的。
關(guān)鍵字: 鋅基合金 合金化元素 阻尼性能
（State Key Laboratory of Solidification Processing, Northwestern Polytecnical University, Xi'an 710072, P. R. China）
Abstract:The effect of Al, Cu, Mg content on microstructure and damping capacity of as-cast zinc based alloy was studied. The damping properties were measured by the cantilever beam technique. Experimental results indicate that as the content of Al increasing in Zn-Al alloy, the content of primary α phase increases, while the content of eutectic decreases gradually and finally disappears completely. The addition of Cu, Mg to Zn-27%Al alloy has no effect on the distribution and the volume fraction of primary α phase. Cu, Mg can solute in Zn-27 %Al alloy, and form intermetallic compound particles MgZn2 and CuZn5, respectively, when their contents are high. When the Al content is in the range of 6%～60%, the zinc-aluminum alloys have high damping capacity. However, Cu, Mg will reduce greatly the damping capacity of Zinc-based alloy. The phase interface slipping between α phase and η phase or the grain boundary viscous sliding may occur when the material is under cyclic loading. Meanwhile, the elastic module of α phase and η phase are different, thus the strain of α phase mismatches that of η phase, which leads to infinitesimal plastic deformation of α phases. Therefore, the effective energy dissipation will be generated in the zinc-aluminum alloy.
Key words: Zinc-based alloy; damping capacity; alloying elements
