Mg对亚共晶Al-10Mg_(2)Si合金组织与力学性能的影响  

Effect of Mg on microstructure and mechanical properties of hypoeutectic Al-10Mg_(2)Si alloy

作　　者：程婷 赵英[1] 秦纪康 伍复发[2] 武晓峰 CHENG Ting;ZHAO Ying;QIN Ji-kang;WU Fu-fa;WU Xiao-feng(School of Mechanical and Vehicle Engineering,Nanchang Institute of Science and Technology,Nanchang 330108,China;School of Materials Science and Engineering,Liaoning University of Technology,Jinzhou 121001,China)

机构地区：[1]南昌工学院机械与车辆工程学院,江西南昌330108 [2]辽宁工业大学材料科学与工程学院,辽宁锦州121001

出　　处：《材料热处理学报》2024年第9期84-91,共8页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51971106);江西省教育厅科技项目(GJJ2202921,GJJ2202905)。

摘　　要：研究了不同Mg含量对含10 mass%Mg_(2)Si的亚共晶Al-Mg-Si合金显微组织、拉伸性能和断裂行为的影响。结果表明:在合金中添加1.2~2.8 mass%的Mg能够减小初生α-Al枝晶的尺寸,适量的Mg明显地细化了合金中的Mg_(2)Si共晶相,并使其形貌由粗大的汉字状转变为短条状、颗粒状和纤维状。共晶Mg_(2)Si的细化归因于Mg原子团簇在其两侧的富集,抑制了共晶Mg_(2)Si的生长,促进了其生长方向的改变。适量的Mg的添加同时提高了合金的强度和塑性,添加2.8 mass%Mg的合金拉伸性能达到最高,抗拉强度、屈服强度和伸长率分别由未添加Mg的232.4 MPa、150.4 MPa和1.5%增加到322.0 MPa、270.4 MPa和6.1%,分别提高了38.6%、79.8%和306.7%。未添加Mg的合金的断裂机制为脆性断裂,添加2.8 mass%Mg的合金的断裂机制转变为韧性断裂。Effect of different Mg contents on microstructure,tensile properties and fracture behavior of hypoeutectic Al-Mg-Si alloy containing 10 mass%Mg_(2)Si was studied.The results show that adding 1.2-2.8 mass%Mg to the alloy can reduce the size of primaryαAl dendrites.The appropriate amount of Mg significantly refines the Mg_(2)Si eutectic phase in the alloy,and transforms its morphology from coarse Chinese character like to short strip like,granular and fibrous.The refinement of eutectic Mg_(2)Si is attributed to the enrichment of Mg atomic clusters on its both sides,which inhibits the growth of eutectic Mg_(2)Si and promotes a change in its growth direction.The addition of an appropriate amount of Mg simultaneously improves the strength and plasticity of the alloy.The tensile properties of the alloy with 2.8 mass%Mg addition reach the highest,the tensile strength,yield strength and elongation increase from 232.4 MPa,150.4 MPa and 1.5%without Mg addition to 322.0 MPa,270.4 MPa and 6.1%,respectively,with an increase of 38.6%,79.8%and 306.7%,respectively.The fracture mechanism of the alloy without Mg addition is brittle fracture,while the fracture mechanism of the alloy with 2.8 mass%Mg addition changes to ductile fracture.

关 键 词：AL-MG-SI合金 Mg 共晶Mg_(2)Si 初生α-Al枝晶 拉伸性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]