加热温度对半固态AZ91D镁合金部分重熔组织的影响

Effects of Heating Temperatures on Microstructure of Semi-solid AZ91D Magnesium Alloy During Partial Remelting

在固液两相区、液相线以及液相线以上温度对AZ91D镁合金半固态坯料进行等温部分重熔试验,研究了加热温度对半固态坯料部分重熔组织的影响。结果表明,半固态坯料部分重熔,晶粒首先发生合并长大,然后再熔断分离块状晶粒,块状晶粒最后再通过Ostwald熟化逐渐球化。随着加热温度的提高,组织演变明显加快,晶粒更加细小。

The semi-solid AZ91D magnesium alloy billets were reheated isothermally at solid-liquid zone temperature,liquids temperature and above liquids stemperature.The effects of heating temperatures on the microstructure of billets were studied.The results have shown that during partial remelting,the grains grown up though coalescence initially,then divorces into lumps.Finally the lumps evolve into spheroids gradually though Ostwald ripening.Rising the heating temperature,the microstructure evolution process is accelerated and the grains are finer.