Influence of High-Speed Ram Transition Position on Porosity and Mechanical Properties of Large One-Piece Die-Casting Al-Si-Mn-Mg Aluminium Alloy

Materials (Basel). 2024 Dec 17;17(24):6169. doi: 10.3390/ma17246169.

Abstract

The high-pressure die-casting process can effectively manufacture aluminium alloy castings with complex shapes and thin wall thicknesses. However, due to the complex flow characteristics of the liquid metal during the mould-filling process, there are significant differences in the mechanical properties of different parts of the casting. This paper analyses the effect of the high-speed ram transition position on porosity and mechanical properties of Al-Si-Mn-Mg aluminium alloys in the high-pressure die-casting (HPDC) process, comparing the 1160 mm and 1200 mm positions. Using a comprehensive methodology that combines CT, tensile tests, and SEM, the research demonstrates that the 1160 mm position improves mechanical properties and reduces porosity, with a larger gap at the near-end of the casting, where the yield limit and elongation of the casting increased by 13% and 25% at 1160 mm compared to 1200 mm, respectively. This result shows that appropriate adjustment of the high-speed ram transition position can effectively optimise the organisational structure of thin-walled castings, and then improve their mechanical properties.

Keywords: aluminium alloy castings; high-pressure die-casting; microstructure analysis; optimisation of casting structure; piston switching position; process parameters.

Grants and funding

This research was funded by [Tianjin Science and Technology Project] grant number [24ZXZSSS00580], [Chongqing Technology innovation and application development project] grant number [08400110], [Youth Talent Support Project of China Society of Automotive Engineers] grant number [QK-20240316-011] and [Research Project of China Automotive and Technology Research Center] grant number [ZX23240003].