摘要
采用约束棒法评定不同浇注温度下Al-7Zn-2.5Mg-Cu合金的热裂倾向,采用OM观察了合金的显微组织。结果表明,不同浇注温度下,合金的显微组织均为等轴晶结构。随着浇注温度升高,合金的晶粒粗化,晶间共晶数量减少,且由连续分布逐渐转变成半连续分布,热裂倾向增大。但浇注温度为680℃时,合金出现浇不足缺陷。在保证该合金充型能力的前提下,降低浇注温度是减少其热裂倾向的有效途径。
Hot cracking susceptibility of AI-7Zn-2.5Mg-Cu alloys under different pouring temperature was evaluated with constrained rob method, the microstructure of the alloy was observed by OM. The results show that the microstrucmre of the alloys under different pouring temperature is all equiaxed grain structure. With increasing pouring temperature, the grain size of the alloys increases, the intergranular eutectic number decreases, and its distribution is transformed from continuous to semi-continuous gradually, hot cracking susceptibility increases. However, when pouring temperature is 680℃, the alloy has the defects of misrun. Under the conditions of ensuring the filling capacity of the alloy, reducing pouring temperature is an effective way to reduce hot cracking susceptibility.
出处
《铸造技术》
CAS
北大核心
2013年第1期72-75,共4页
Foundry Technology
