中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 34 No. 2 February 2024 |
（1. Chemistry Department, Xi’an Jiaotong-Liverpool University, Suzhou 215000, China;
2. Yangtze Delta Region Institute of Advanced Materials, Suzhou 215000, China;
3. Key Laboratory for Light-weight Materials, Nanjing Tech University, Nanjing 210009, China;
4. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
5. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China;
6. IM Motors, Shanghai 200020, China）
Abstract: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 of α-Al(Fe/Mn)Si phase played an important role in the fluctuation of elongation, and specimens with higher number density of α-Al(Fe/Mn)Si particles exhibited deteriorated elongations. In addition, the increase in the number density of α-Al(Fe/Mn)Si phase was attributed to local higher cooling rates.
Key words: high-pressure die-casting; Al-7Si-0.2Mg alloy; porosity; α-Al(Fe/Mn)Si phase; ductility
