1990 Volume 8 Issue 2 Pages 204-210
It is the ultimate purpose of this investigation to elucidate the fundamental phenomena in cooling and solidification process and to establish reasonably the methods of estimating hot cracking sensitivity and preventing Al alloy weld from hot cracking.
In this report, temperature measurement was carried out by CA thermocouple in coiling and solidification process on TIG arc spot welds of commercial Al alloy 2024 and 5083 and various analyses were performed.
On the basis of the measured value, the authors made Continuous Cooling Solidification Process diagram (CCSP diagram) showing the relation among passed time from arc stop, phase change and the position of welds.
By using the CCSP diagram, the authors could investigate the solidification process of the welds. With regard to fraction solid cooling rate (cooling rate in solid-liquid coexisting zone), it was found that the cooling rate at every definite fraction solid was more meaningful than one in a whole solidification time.
Increasing behavior of fraction solid were very different between 2024 and 5083 Al alloy at the latter stage of solidification process in the molten pool.
