硅相钝细化处理与热挤压对Al-25Si合金组织的影响  

Effect of Si phase passivation and hot extrusion on microstructure of aluminum-25Si alloy

作　　者：仇平 杨瑞青[1] 石钰[1] QIU Ping;YANG Ruiqing;SHI Yu(Northeast Light Alloy Co.,Ltd.,Harbin 150060,China)

机构地区：[1]东北轻合金有限责任公司,黑龙江哈尔滨150060

出　　处：《轻合金加工技术》2023年第1期30-41,共12页Light Alloy Fabrication Technology

摘　　要：对Al-25Si合金进行硅相钝细化处理和热挤压的复合处理,研究工艺参数对Al-25Si合金组织形态的影响。结果表明:对铸态Al-25Si合金进行硅相钝细化处理,能够使合金中的硅相尖角钝化,保温温度越高、保温时间越长,硅相尖角钝化效果越明显;但保温温度过高、时间过长,硅相的粗化明显,尖角钝化效果变弱,反而不能改善硅相的形态。热挤压可以明显使共晶硅均匀分布在合金中,但是对初生硅的尺寸、形状几乎没影响;保温时间和温度对挤压态Al-25Si合金中的硅相有很大的影响,当温度达到合金的液相线时,合金的组织形态变化明显。随着保温温度和时间增加,硅相的尺寸增加,球化效果变好。但温度过高、时间过长会发生过烧氧化的现象。The effect of the process parameters on the microstructure of Al-25Si alloy was studied by Si phase passivation and extrusion treatment of Al-25Si alloy.The results show that Si phase passivation of cast Al-25Si alloy can make the silicon phase in the alloy passivated.With the increase of the holding temperature and time,the passivation effect of the silicon phase is more obvious.But when the insulation temperature is too high,holding time is too long,the coarsening of the silicon phase is obvious,the passivation effect becomes weak,and can not improve the silicon phase morphology.The hot extrusion can make the eutectic silicon evenly distributed in the alloy,but it has little effect on the size and shape of the primary silicon.Different holding time and temperature have a great influence on the silicon phase in extruded Al-25Si alloy.When the temperature reaches the liquid phase of the alloy,the microstructure of the alloy changes obviously.With the increase in temperature and time,the size of the silicon phase increases and the spheroidization effect becomes better.But the phenomenon of burning oxidation will occur when the temperature is too high and the time is too long.

关 键 词：Al-25Si合金 钝细化处理 热挤压 形状因子 

分 类 号：TG146.21[一般工业技术—材料科学与工程]