Al-Al_4C_3细化剂和超声场对纯Mg组织的影响  

EFFECTS OF Al-Al_4C_3 REFINER AND ULTRASONIC FIELD ON MICROSTRUCTURES OF PURE Mg

作　　者：高声远[1] 乐启炽[1] 张志强[1] 崔建忠[1] 

机构地区：[1]东北大学材料电磁过程研究教育部重点实验室,沈阳110819

出　　处：《金属学报》2010年第12期1495-1500,共6页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展计划项目2007CB613701和2007CB-613702;国家自然科学基金项目50904018;50974037和51004032;中央高校基本科研业务费专项资金项目90409002和90209002;教育部新世纪优秀人才支持计划项目NCET08 0098;中国博士后科学基金项目20100471648资助~~

摘　　要：在不同Al-Al_4C_3细化剂添加量条件下,对纯Mg熔体进行孕育处理.当添加质量分数为1.0%Al Al_4C_3细化剂时细化效果最佳,α-Mg晶粒平均尺寸由毫米级降至106μm.在纯Mg熔体中施加不同功率超声场,当施振功率为600 W时细化效果最好.研究表明,空化泡破碎产生的过冷对形核具有促进作用,空化泡的破裂及声流对熔体的搅动使得细小枝晶破碎,形成新的结晶核心,这一过程对形核起主要作用.功率超声与Al-Al_4C_3细化剂共同作用于纯Mg熔体过程,可以显著细化晶粒.其机理为超声对杂质的"活化"作用.The melt of pure Mg was inoculated at the conditions of different addition amounts of Al-Al_4C_3 refiner.When adding 1.0%Al-Al_4C_3 refiner,the refining effect is the best and the average grain size ofα-Mg is reduced from millimeter level to 106μm.Ultrasound fields with different power levels were applied on the melt of pure magnesium and the best refining effect was obtained when the power was 600 W.The results show that the undercooling formed by breakdown of cavitation bubbles may have a promoting effect to nucleate.The breakdown of cavitation bubbles and the agitations of acoustic stream on the melt cause the fragmentation of fine dendritic crystal which could form new crystallization nuclei,this process plays the main role for nucleating in the melt.The combined application of ultrasound and Al-Al_4C_3 refiner to the melt of pure Mg could significantly refine its grain.The mechanism would be an the activation effect of ultrasound on the impurities in the melt.

关 键 词：超声场 纯MG Al_4C_3 晶粒细化 

分 类 号：TG146.2[一般工业技术—材料科学与工程]