Hot tearing tendency of binary Al-033% Cu and Al-013% Si alloys was studied by the new hindered hot tearing test, "I-beam test". Insulator (0.5mm in thickness) was pasted on the middle of the mold wall, in order to locate tears only in the middle of the test bars.
Hot tearing tendency of Al-Cu alloys was most increased at 12% Cu, and as the Cu content increased up to 15% Cu, hot tearing tendency was decreased. The healig phenomenon was visible in Al-2033% Cu alloys. In binary Al-Si alloys, hot tearing tendency was most increased at about 0.5% Si. As the Si content increased up to 4% Si, hot tearing tendency was decreased, and in Al-913% Si alloys, the healing phenomenon was visible.
Hot tearing was occured by "I-beam test" in the alloys it had not been recognized before by the previous test. So it is thought that hot tearing is the universal phenomenon in the solidification process. These hot tearing tendency was not explained by the temperature range of the semi-solid region.
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