熔体过热处理对Mg_2Si/Al-Si复合材料显微组织的影响  

Effects of Melt Superheat Treatment on Microstructures of Mg_2Si/Al-Si Composite Materials

作　　者：钟特 钱鑫[1] 成志刚[1] 刘扬[1] 王东雷[1] 陈淑英[1] 

机构地区：[1]辽宁工业大学材料科学与工程学院,辽宁锦州121001

出　　处：《铸造技术》2016年第10期2067-2071,共5页Foundry Technology

摘　　要：通过原位反应制备Mg_2Si增强Al基复合材料,研究熔体过热处理温度和保温时间对Mg_2Si/Al-Si复合材料组织与性能的影响,确定最佳的工艺参数。结果表明:在本实验条件下,熔体过热处理的最佳工艺为820℃保温30 min,初生Mg_2Si接近于球状,平均晶粒尺寸为17μm,共晶Si由粗大的枝晶状变成细小的颗粒状,共晶Mg_2Si由汉字状变成短棒状,分布较均匀。未进行保温处理时,初生Mg_2Si的晶粒尺寸随着过热温度的提高而减小;过热温度低于870℃时,初生Mg_2Si的晶粒尺寸随保温时间的延长而减小;过热温度高于870℃时,初生Mg_2Si晶粒尺寸随保温时间的延长而急剧增大。The Mg2 Si reinforced Al matrix composite was prepared by in-situ reaction,and the influences of the superheat temperature of the melt and the holding time on the microstructure and properties of Mg_2Si/Al-Si composite were studied to determine the best parameter.The results show that the best parameter of the melt superheat treatment is that the superheating temperature is 820 ℃ and the holding time is 30 min.The morphology of the primary Mg2 Si is close to the sphere and the average grain size is 17 μm.The coarse dendritic eutectic Si turns into the small granular.The morphology of the eutectic Mg2 Si changes from the Chinese script type to the short stick and the distribution of it is more uniform.The grain size of the primary Mg2 Si decreases with the increase of the superheating temperature without the insulation treatment.The grain size of the primary Mg2 Si decreases with the increase of the holding time when the superheating temperature is below 870 ℃.When the superheating temperature is higher than 870 ℃,the grain size of the primary Mg2 Si increases rapidly with the increase of holding time.

关 键 词：复合材料 凝固组织 初生Mg_2Si 熔体过热温度 保温时间 

分 类 号：TB333[一般工业技术—材料科学与工程]