孔隙和α-Al(Fe/Mn)Si相对高压压铸Al-7Si-0.2Mg合金塑性的影响  

Effect of porosity andα-Al(Fe/Mn)Siphase on ductility of high-pressure die-casting Al−7Si−0.2Mg alloy

作　　者：杨雨童 黄诗尧 郑江[4] 杨莉[1] 程晓农 陈睿凯[6] 韩维建 Yu-tong YANG;Shi-yao HUANG;Jiang ZHENG;Li YANG;Xiao-nong CHENG;Rui-kai CHEN;Wei-jian HAN(Chemistry Department,Xi’an Jiaotong-Liverpool University,Suzhou 215000,China;Yangtze Delta Region Institute of Advanced Materials,Suzhou 215000,China;Key Laboratory for Light-weight Materials,Nanjing Tech University,Nanjing 210009,China;College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China;School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China;IM Motors,Shanghai 200020,China)

机构地区：[1]西交利物浦大学化学系,苏州215000 [2]长三角先进材料研究院,苏州215000 [3]南京工业大学先进轻质高性能材料研究中心,南京210009 [4]重庆大学材料科学与工程学院,重庆400044 [5]江苏大学材料科学与工程学院,镇江212013 [6]智己汽车科技有限公司,上海200020

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第2期378-391,共14页中国有色金属学报（英文版）

基　　金：financially supported by the Fundamental Research Funds for the Central Universities,China(No.2020CDJDPT001);the Chongqing Natural Science Foundation,China(No.cstc2021jcyj-msxm X0699)。

摘　　要：采用高压压铸工艺制备两批次不同尺寸的Al-7Si-0.2Mg(质量分数,%)合金,获得显微组织和孔隙非均匀分布的薄壁铸件,并对比研究孔隙和显微组织对铸态合金塑性的影响。结果表明:不同铸件和不同位置样品的伸长率有较大波动(9.7%~17.9%)。当合金存在大面积孔隙时,有效承载面积减小导致由孔隙产生的应力集中使合金伸长率显著降低。当合金只存在小面积孔隙时,塑性变形过程中合金中的α-Al(Fe/Mn)Si相先于共晶硅相发生脆性断裂,α-Al(Fe/Mn)Si相的数量密度对伸长率的波动起主导作用,具有高数量密度α-Al(Fe/Mn)Si相试样的伸长率显著降低。此外,局部较高的冷却速率导致铸件α-Al(Fe/Mn)Si相数量密度的增加。High-pressure die-casting(HPDC)was used to develop two sizes of Al−7Si−0.2Mg(mass fraction,%)thin-plates with similar composition.Thin-plate castings with varying degrees of porosities and uneven microstructures were obtained and their effects on ductility were investigated.The results showed that the elongations of specimens from different castings and different positions fluctuated greatly(9.7%−17.9%).Elongation dropped sharply when specimens contained large porosities,which could be ascribed to stress concentration due to the reduction of the effective bearing area.However,for samples with small porosities,α-Al(Fe/Mn)Si phase cracked prior to eutectic phase during plastic deformation.The number density ofα-Al(Fe/Mn)Si phase played an important role in the fluctuation of elongation,and specimens with higher number density ofα-Al(Fe/Mn)Si particles exhibited deteriorated elongations.In addition,the increase in the number density ofα-Al(Fe/Mn)Si phase was attributed to local higher cooling rates.

关 键 词：高压压铸 Al-7Si-0.2Mg合金 孔隙 α-Al(Fe/Mn)Si相 塑性 

分 类 号：TG249.2[金属学及工艺—铸造]