Effect of combined addition of Al-Ti-B ribbon and Zr element on the microstructure, mechanical and damping properties of ZA22 alloy

Publication date: 5 August 2017
Source:Materials & Design, Volume 127
Author(s): Nan Li, Xiaojing Liu, Qingzhou Wang, Chunxiang Cui, Fuxing Yin, Xiangwei Ji, Zhixian Jiao
A novel Al-5Ti-1B ribbon was prepared and used as inoculant to refine the grains of Zn-Al eutectoid (ZA22) alloy with the aim to significantly enhance the mechanical properties while remaining the high damping capacity. It was found that compared with the commercial Al-5Ti-1B rod the present ribbon had better refining effect on the ZA22 alloy due to its finer and more uniformly distributed TiB2 and L12-Al3Ti particles formed during rapid cooling process. It has been confirmed that both of the two kinds of particles could act as effective heterogeneous nucleation sites of α-Al phase, and then led to the refinement of α-Al grains. The combined addition of Al-5Ti-1B ribbon and Zr element could achieve the best refining effect because Zr could further promote the heterogeneous nucleation and hinder the growth of α-Al grains. Properties tests illustrated that with the decrease of average grain size, the tensile strength, elongation and hardness of the ZA22 alloy increased obviously because of the fine-grain strengthening and dispersion strengthening effects, while the damping showed different variation patterns within different temperature regions, which has been ascribed to the synthetic effect of two opposite influencing factors.

Graphical abstract

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