摘要
在镁合金中添加适量的Sr,不仅可以降低过冷度,且易吸附在固/液界面的前沿形成富Sr的吸附膜,降低晶粒生长速度,从而细化晶粒。细小的晶粒有利于提高镁合金液的补缩能力,减少显微缩松,增加铸件的致密度。Sr与H2反应生成SrH2,减少氢气孔的析出。此外,在Mg-Al合金中加入Sr可以生成一些高温稳定的新相(Al10Mg13Sr),明显改善镁合金的高温蠕变性能和抗热裂性能。
Adding proper amount of Sr can not only decrease the super-cooling but also form adsorptive Sr films on the boundaries of growing crystals, resulting in a reduction of the grain growth rate, in turn, the formation of fine-grained structure. Fined-grain can improve inter-granular capillary feeding of the liquid metal, resulting in the reduction of micro-porosity and the increase of density. When Sr is present in Mg and its alloys, SrH2 will be formed dudng solidification. Thus, the formation of gas pores is restricted. When adding Sr to the Mg-Al alloy, some new stable phases （Al10Mg13Sr） are formed, which can give excellent creep resistance and heat cracking resistance performance.
出处
《铸造》
EI
CAS
CSCD
北大核心
2005年第11期1121-1124,共4页
Foundry
基金
湖北省自然科学基金(2004ABA110)
武汉理工大学博士基金(471-38300843)
武汉理工大学基金(2003XJJ010)。
关键词
锶
镁合金
晶粒细化
显微缩松
高温蠕变
strontium
magnesium alloy
gain refining
micro-porosity
high temperature creep
