Effect of gas-induced semisolid process on solidification parameters and dendrite coherency point of Al–4.3Cu alloy using thermal analysis

摘要: Semisolid processing of Al–4.3%Cu (A206) alloy was carried out using gas-induced semisolid (GISS) process in different conditions. The flow rate inert gas, 1, 2, and 4 L min−1, starting temperature for gas purging (the superheated melt), 670, 660, 650 °C, the duration purging, 10, 20, 30 s, were three key variables which changed during this investigation. Thermal analysis successfully implemented through CA-CCTA technique GISS samples as well conventionally cast sample. two-thermocouple thermal utilized to determine dendrite coherency point sample results showed that into melt led drop its liquidus temperature. In fact, copious nucleation is induced by cooling effect bubbles. delays from 644.2 637.3 °C leads increase solid percentage 9 21% at therefore enhance casting characteristics. It found molten metal, regardless parameters, microstructural modification fully dendritic globular structure. Microstructural evaluation best included fine grains 76 μm average size with high level globularity 0.86 achieved a started 670 °C time 20 s 4 L min−1.