微量钛硅对热浸镀锌铝合金金相组织的影响探究

通过向热浸镀锌铝合金中分别掺入微量钛、硅元素, 探究不同含量的钛、硅对锌合金金相组织的影响。结果表明, ZnAl系合金Ti含量在0~0.01%之间, 其晶粒从多向生长转为单向生长, 第三相分布均匀;Ti含量在0.01%~0.02%之间, 其晶粒从单向生长转为多向生长, 组织形态变化较大, 随着第三相增加, 出现局部集中现象。随着Al含量增加, ZnAlSi系合金中第三相Si相从分布在富铝相和富锌相向富铝相区域集中。Ti元素对合金组织细化效果优于Si元素, 对合金组织影响较为显著。

Effects of Silicon and Titanium on the Metallographic Structure of Hot-Dip Galvanizing Zinc Alloys

Traces of titanium and silicon elements were added respectively into a hot-dip galvanizing Zn-Al alloy in an experiment to probe into the effects of adding different amount of Ti and Si on the metallographic structure of zinc alloys. Results show that for ZnAl alloy, with Ti content within the range of 0~0.01%, its crystal grain is transformed from multi-directional growth to single directional one and the third phase has uniform distribution; with Ti content within the range of 0.01%~0.02%, its crystal grain has the growth transformed from single-direction to multi-direction, with great change in the structural morphology. Furthermore, with an increase of the third phase, a phenomena of local concentration occurs. With the increase of Al content, third phase Si in ZnAlSi alloy that is previously distributed in the Al-rich phase and Zn-rich phase, has turned to be concentrated in Al-rich phase. It is found that Ti element, compared to Si element, has greater effect on the alloy microstructure refinement, showing a remarkable impact on the alloy structure.