晶粒组织对Al-Mg-Si合金性能的影响

Effects of Grain Structure on the Properties of Al-Mg-Si Alloy

摘要: 本文制备了3种不同晶粒组织的Al-Mg-Si合金。通过拉伸试验和晶间腐蚀试验研究了晶粒组织对力学性能及腐蚀性能的影响。结果表明，Al-Mg-Si合金的强度与耐蚀性能均与基体晶粒组织结构显著相关，亚晶界、变形组织含量较大的纤维晶粒组织试样强度较粗大的完全再结晶组织试样提高约35 MPa，但其耐晶间腐蚀性能较差。电子背散射衍射(EBSD)和透射电子显微镜(TEM)观察结果表明，晶粒组织结构引起了合金内部析出相的析出行为产生显著差异，从而导致了相同合金成分的不同试样力学性能和耐晶间腐蚀存在显著差别。

Abstract: Three kinds of different grain structures of Al-Mg-Si alloy samples were prepared in this paper. Tensile tests, intergranular corrosion tests were conducted to study the effects of grain structures on the mechanical properties and corrosion resistance of the alloy. The results showed that the strength and corrosion resistance closely depended on the grain structures. The fiber grains sample with higher content of sub-grains and deformed structures ex-hibited higher strength (by approximately 35 MPa) and lower corrosion resistance, when compared with the fully recrystallized samples. Observations through backscattered electron diffraction (EBSD) and transmission electron microscope (TEM) showed that the precipitation behavior of the alloys were significantly affected by the differences of the grain structures, thus, it resulted in significant differences of the mechanical properties and corrosion resistance of the alloys with the same chemical compositions but different grain structures.