摘要
用热裂环法考察合金的热裂倾向性 ,并对合金的冷却曲线和铸态组织进行了分析。Zn加入Mg 9Al合金降低了合金的凝固结束温度 ,平均每增加 0 .1% ,合金的凝固结束温度降低 0 .7℃。Zn促进了Mg17Al12 相在晶界的析出 ,降低了凝固结束温度 ,并显著增加了合金的热裂倾向性。RE对Mg 9Al合金的热裂倾向性和凝固结束温度影响很小。但当Zn含量超过 0 .8%时 ,RE的加入可以显著降低Mg 9Al
Mg 9Al alloy was adopted as master alloy. Zinc and rare earth (RE) were added to the maximum quantity of1.2% and 1.6%, respectively. Their effects on the hot tearing susceptibility were investigated using crack ring molds. Cooling curves and as cast structure were analyzed. Zn additions descend the end solidifying temperature of Mg 9Al alloy (about 0.7 ℃ per 0.1% Zn addition in average). In Mg 9Al alloy, Zn promotes the precipitation of Mg 17 Al 12 in grain boundaries and increases the hot tearing susceptibility coefficient (HSC) distinctly. RE additions have little effect on the HSC and the end solidifying temperature of Mg 9Al, while they can descend the HSC of Mg 9Al Zn alloys notably when the content of zinc is excess of 0.8%.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2003年第1期40-45,共6页
The Chinese Journal of Nonferrous Metals
基金
国家"八六三"高技术计划重点课题基金资助 (2 0 0 2AA3 3 10 3 0 )
关键词
镁合金
热裂倾向性
锌
稀土
凝固
Mg Al alloys
Zinc
RE
hot cracking
solidification
