| 초록 |
During a solidification process in a variety of casting processes, aluminum alloy cast components experience considerable changes in their mechanical properties, which subsequently adversely affect the residual stresses and distortion in the cast parts. In the present study, the mechanical properties of aluminum-silicon alloy, AA365, undergoing heat treatment processes such as T4, T5, and T6 were investigated to see the effects of cooling rate on mechanical properties of AA365. The effects of different cooling rates on the mechanical properties of AA365 have been analyzed by microstructure investigation to understand the mechanisms of the mechanical property changes. In addition, the residual stresses with different heat treatment conditions have been measured and correlated with the microstructural behavior of AA365. Recently developed 'Pulstec portable X-ray residual stress analyzer, HPDC showed reliable residual stress measurement results for a specimen with a particle size of less than 10μm. A 10 μm-size Al-Si-Mn-Fe phase causing the initial stress concentration was confirmed, and Mg-rich phase, which forms a secondary phase, can be confirmed without Mg as an aluminum matrix at the time of cold rolling. This study aims to provide a better understanding of the residual stress by revealing the correlation between cooling rate, microstructure and residual stress of Dissimilar-casting part using aluminum die casting materials. |
