CAJ | 학술논문

对不同慢压射速度条件下真空辅助对AZ91D镁合金压铸件组织及力学性能的影响进行了评估。在联合有自行改进的TOYO真空系统的TOYO BD-350V5型冷室压铸机上制备片状AZ91D镁合金压铸件。研究发现，充型时型腔真空压力随着慢压射速度的升高呈现3次方增长，导致真空辅助对压铸件中气孔的降低能力随着慢压射速度的降低而下降。常规和真空压铸件中压室预结晶组织(ESC)含量随着慢压射速度的变化趋势相似。在较低慢压射速度时，真空压铸件拉伸性能受ESC含量的影响很大，随着慢压射速度的升高，真空压铸件中气孔含量的影响将变得显著。
대불동만압사속도조건하진공보조대AZ91D미합금압주건조직급역학성능적영향진행료평고。재연합유자행개진적TOYO진공계통적TOYO BD-350V5형랭실압주궤상제비편상AZ91D미합금압주건。연구발현，충형시형강진공압력수착만압사속도적승고정현3차방증장，도치진공보조대압주건중기공적강저능력수착만압사속도적강저이하강。상규화진공압주건중압실예결정조직(ESC)함량수착만압사속도적변화추세상사。재교저만압사속도시，진공압주건랍신성능수ESC함량적영향흔대，수착만압사속도적승고，진공압주건중기공함량적영향장변득현저。
The effects of vacuum assistance on the microstructure and mechanical properties of high-pressure die cast AZ91D alloy at different slow shot speeds were evaluated. Plate-shaped castings of AZ91D alloy were carried out on a TOYO BD-350V5 cold chamber die casting machine incorporated with a self-improved TOYO vacuum system. It was found that the vacuum pressure in the die cavity at the beginning of mold filling increases with the increase of slow shot speed, following a cubic polynomial curve, resulting in a decline in the porosity-reduction ability of vacuum assistance with the increase of slow shot speed. The externally solidified crystal (ESC) contents in conventional and vacuum die castings behave similar against the slow shot speed. The tensile properties of vacuum die castings were strongly influenced by the ESC content at relative low slow shot speeds. With the increase of slow shot speed, the influence of the gas porosity level in vacuum die castings would get prominent.