Microstructure and impact properties of slow injection A356 die castings with partial squeeze

作者：Bai, Yan-Fei; Zhao, Hai-Dong^*; Li, Yuan-Yuan; Kang, Zhi-Xin

来源：Chinese Journal of Nonferrous Metals, 2010, 20(3): 442-450.

• Area fraction
• Eutectic si
• Fracture mechanisms
• Impact absorbed energy
• Impact property
• Secondary dendrite arm spacing
• Si-particle
• T6 heat treatment

The microstructures and impact properties of slow injection A356 die casting with partial squeeze were investigated. The results show that as for the as-cast castings, eutectic Si particles are characterized as fibrous or long acicular shape as well as in homogenous distribution, and the impact absorbed energy varies from 1.17 to 2.35 J. After T6 heat treatment, the eutectic Si particles become small granular or short bacilliform, and the aspect ratio and area fraction of Si particles decrease evidently. The energy of the T6-treated castings is 1.45-3.80 J, which is higher than that of the as-cast castings. Furthermore, the fracture mechanisms of different regions in the castings were analyzed and discussed. Through mathematical regression analysis, it is indicated that the impact property depends on both the aspect ratio and secondary dendrite arm spacing of the Si particles.

• 出版日期2010-3
• 单位华南理工大学