高硅铝合金粉末的高温空气氧化预处理工艺

通过对铝硅合金粉末采用高温空气氧化预处理,然后进行包套热挤压,制备了Al-12Si共晶及Al-30Si过共晶高硅铝合金材料。利用氧分析仪、金相显微镜、扫描电镜及透射电镜等分析检测设备,对预处理粉末的氧含量与组织及所制备材料组织进行分析比较。结果表明：铝硅合金粉末氧含量随氧化时间延长而逐渐增加,氧化速度随氧化时间延长而下降;粉末颗粒表面氧含量明显高于颗粒内部的;在相同氧化时间内,Al-30Si粉末氧含量的增加大于Al-12Si的,Al-30Si粉末的氧化速度更快;合金粉末经高温空气氧化预处理后,晶粒出现不同程度的长大,Al-12Si共晶合金的晶粒长大不明显,而Al-30Si过共晶合金晶粒长大十分明显。

Pretreatment technology of high-silicon aluminum alloy powder in high temperature atmosphere oxidation

In order to fabricate high-silicon aluminum alloy material,eutectic Al-12Si and hypereutectic Al-30Si alloy powders were pretreated in high temperature atmosphere oxidation,then they were canned and extruded into Al alloy materials.Oxygen analyzer,optical microscopy,scanning electron microscopy(SEM) and transmission electron microscopy(TEM),were used to study and compare the oxygen content and microstructure of pretreatment powders and the microstructure of materials.The results indicate that the oxygen content of the aluminum silicon alloy powders increases and the oxidation rate decreases with prolonging oxidation time.The oxygen content on powder surface is higher than that in inner particle.The oxygen content of Al-30Si powders is higher and the oxidation rate is quicker than that of Al-12Si powders in the same oxidation time.The crystal particles of alloy powders grow up in different degrees after pretreatment in high temperature atmosphere oxidation,the growth of size of Al-12Si eutectic alloy particles is not obvious,but that of Al-30Si hypereutectic alloy is very obvious.