合金元素对A7N01铝合金焊接接头断裂韧性的影响

Effect of Alloying Elements on the Fracture Toughness of A7N01 Aluminum Alloys Welded Joints

A7N01铝合金是制造高速列车底架结构的关键材料,其合金构成中含有Zn、Mg等主元素,Mn、Cr、Zr,、Ti、Cu等微量元素以及杂质元素Fe、Si等元素。以具有四种不同合金含量的铝合金材料为研究对象,并制备了焊接接头,测试了不同焊接接头的断裂韧性。研究结果表明:决定A7N01铝合金母材断裂韧性性能的主要因素在于元素含量及配比,而对于焊接接头,除了元素含量及配比的影响,气孔的分布数量及体积对于断裂韧性起到了较大的影响。因此,在制备A7N01铝合金焊接接头时,除了要考虑合金元素的影响,更应该控制接头中气孔的生成,提高接头的质量。

A7N01 aluminum alloy is the key material for manufacturing the underframes of the high speed trains The components include the major elements of Zn and Mg, the minor elements of Mn, Cr, Zr, Ti, and Cu, and impurity elements of Fe and Si. This paper focus on the A7N01 aluminum alloys with four types of alloying elements and fabricated four types of welded joints. The fracture toughness of the four types of base materials and welded joints were tested. The results show that the key factor that affects the fracture toughness of the base materials arethe contents and ratios of the elements. But as for the fracture toughness of the welded joints, the key factors include not only the content and matching of the elements, but also the volume and quantity of the porosity. To improve the quality of the welded joints, not only the elements composition but also the formation of porosity should be taken into consideration..