半固态A356合金重熔加热过程中的热稳定性

Heat Stability of Semi-Solid A356 Alloy during Remelting Process

利用电阻炉加热,采用电子显微镜及图象分析仪,研究了近液相线铸造A356铝合金在二次加热过程中的组织变化。结果表明:近液相线铸造铝合金A356在580℃～590℃加热,保温10 min,晶粒仍保持细小、近似等轴的组织特点。随着加热温度的升高和保温时间的延长,初生相尺寸增加较小,具有较高的热稳定性。

Using resistance furnace, the structure of A356 aluminum alloy casted by nearby liquidus semi-continuous was studied during remelting by means of electron microscope and image analysis apparatus. The results show that the crystal keeps fine non-dendrite during remelting when heated at 580degreesC similar to 590degreesC and heat preservation 10min. The microstructure of A356 alloy keeps higher heat stability during reheating because the size of the firstling increases inconspicuously along with remelting temperature ascending and heating time increasing.