新型模具ZA合金TIG焊缝显微组织及相结构分析

Investigation on Microstructure and Phase Structure in TIG Weld of a New Type of ZA Alloy for Mould Material

用光学显微镜、扫描电镜、透射电镜等分析手段 ,对新型模具ZA合金TIG焊对接焊缝的显微组织及相结构进行了研究分析。结果显示 ,新型模具ZA合金用TIG方法进行焊接 ,焊缝组织形态主要是柱状树枝晶和少量的等轴晶 ;室温组织是由 η(Zn)相、α(Al)相、β′(ZnCu)相和Al4Cu9、CuTi2 、Al7Cu3 Mg6化合物组成。焊缝组织细密 ,其中有细薄的 η和α层片组织 ,且有许多细小的位错及位错环。用TIG方法焊接新型模具ZA合金 ,焊缝组织的细化及细小的化合物都起到了强化作用 ,这有利于提高焊缝的力学性能。

Microstructure and phase structure of weld seam of a new type of ZA alloy for mould material ,which was processed by TIG welding, were investigated by optical microscopy and transmission electron microscopy (TEM). It was shown that after the ZA alloy was processed by TIG welding,the weld seam consists mainly of columnar dendrites and a small amount of equi axial crystals; the microstructUres at room temperature are composed of η(Zn) phase,a(Al) phase, β ' (ZnCu) phase and compounds of Al 4Cu 9, CuTi 2, Al 7Cu 3Mg 6. The microstructure of the weld seam is fine, some fine and thin lamellar η and α ,fine dislocation and dislocation loops are found in it. After the new type of ZA alloy for mould material was processed by TIG welding,the fine microstructure of the weld seam and fine compounds in the weld seam intensify the material and improve the mechanical properties of the weld seam.