Effect of Mold Preheat Temperature on Solidification Crack Strength of AC2B Aluminum Alloy

The effect of the mold preheat temperature on the solidification crack strength was investigated in AC2B aluminum alloy. A tension type apparatus as part of a solidification crack test which could measure the stress-strain relationship quantitatively was utilized. The evaluation of the solidification crack strength with varying mold preheat temperatures was performed by the test procedure established in this research. When the mold preheat temperatures were 250C, 150C and 50C, the solidification crack strengths were found to be 7.8 Kgf/cm, 12.9 Kgf/cm and 28.6 Kgf/cm, respectively. In the same way, when the mold preheat temperatures were 250C, 150C and 50C, the corresponding temperatures of the failure sites were 610C, 600C and 571C, and the calculated solid fractions were 14.0%, 29.3% and 50.8% when the specimens failed, respectively. The solidification crack strength increased in proportion to the solid fraction of the failure site. The solidification crack strength obtained in this test is assumed to reflect the effects of metallurgical factors on the thermo-plastic characteristics of a solidifying alloy such as the grain size of the solid, the grain morphology, and the distribution of solid grain.