CAJ | 학술논문

开发一种半固态金属浆料制备技术,即引晶法,研究工艺参数对半固态A356铝合金浆料组织的影响,讨论球状初生α(Al)晶粒的形成机制和形貌控制.结果表明:当制备浆料为4kg、引晶尺寸为10 mm、加入量为3.5％、倾倒温度为611-617°C时,半固态浆料中初生α(Al)晶粒的平均直径可达40-75 un,形状因子可达0.82-0.89.当引晶尺寸为10mm、倾倒温度为613°C、加入量为2％-4％时,初生α(Al)晶粒的平均直径可达45-82μm,形状因子可达0.78-0.88.倾倒温度的降低或者引晶加入量的适当增加,可以改善初生α(Al)晶粒的组织.当QR=QA、Rb=Rc时,只要倾倒温度适宜就可以制备优质半固态浆料.引晶熔化时产生的枝晶碎块是半固态浆料中初过α(Al)晶粒的直接来源,形成的温度过冷区也有利于异质形核.
개발일충반고태금속장료제비기술,즉인정법,연구공예삼수대반고태A356려합금장료조직적영향,토론구상초생α(Al)정립적형성궤제화형모공제.결과표명:당제비장료위4kg、인정척촌위10 mm、가입량위3.5％、경도온도위611-617°C시,반고태장료중초생α(Al)정립적평균직경가체40-75 un,형상인자가체0.82-0.89.당인정척촌위10mm、경도온도위613°C、가입량위2％-4％시,초생α(Al)정립적평균직경가체45-82μm,형상인자가체0.78-0.88.경도온도적강저혹자인정가입량적괄당증가,가이개선초생α(Al)정립적조직.당QR=QA、Rb=Rc시,지요경도온도괄의취가이제비우질반고태장료.인정용화시산생적지정쇄괴시반고태장료중초과α(Al)정립적직접래원,형성적온도과랭구야유리우이질형핵.
A preparation technology of semi-solid metal slurry introducing grain process (IGP) was developed.The effects of processing parameters on the microstructures of the semi-solid A356 Al-alloy slurries were investigated,and the formation mechanism and morphology controlling of the spherical primary α(Al) grains were discussed.The results show that when the preparing slurry is 4 kg,IG size is 10 mm,dosage is 3.5％ and dumping temperature (DT) is 611-617 °C,the mean diameter of the primary α(Al) grains in the semi-solid slurries can reach 40-75 μm and the shape factor can reach 0.82-0.89.When the IG size is 10 mm,DT is 613 ℃ and dosage is 2％-4％,the mean diameter can reach 45-82 μm and the shape factors can reach 0.78-0.88.With decreasing DT or increasing dosage properly,the primary α(Al) grain morphology is better.When QR=QA and Rb=Rc,as long as the DT is suitable,excellent semi-solid slurry can be produced.As a result ofthe IG melting,a large amount of dendritic fragments can become the direct source of the primary α(Al) grains.Meanwhile,many undercooled areas are formed,where abundant prirnary α(Al) grains are multiplied by heterogeneous nucleation.