摘要
研究了354合金的时效强化行为。试验结果表明,随着时效温度的升高,时效硬化速率增加而时效硬化能力降低。同时发现,在一定温度以上时效,其硬化曲线上出现了两个硬化峰,并且第一个峰值大于第二个峰值。透射电镜试验分析证实,时效硬化的"双峰"现象与时效析出相的析出序列有关,第一个硬化峰主要是由GP区(主要为GPⅡ区)的强化引起的,而第二个时效硬化峰则主要是由亚稳相θ′(Al2Cu)和β′(Mg2Si)的强化效果造成的,同时孕育期较长的S′(Al2CuMg)相的析出也可能是引起第二个峰值的一个重要原因。
The age hardening characteristics of 354 alloy have been investigated in this paper. The amount and density of GP zone is the key to age hardening, while the density and size of GP zone are mainly decided by the aging temperature. It is shown that the rate of age hardening is raised, but the capability of age hardening reduced with the increase of aging temperature. Two peaks in aging hardening curves have been found also as the aging temperature was raised to a fixed temperature. The result of TEM Observation proved that this phenomenon is related to the precipitation sequence; the first peak is mainly caused by GP zone, and the second one mainly caused by metastable phase θ′(Al2Cu)and β′(Mg2Si),as well as S′(Al2Cu Mg).
出处
《铸造》
CAS
CSCD
北大核心
2003年第6期390-394,共5页
Foundry
关键词
铸造铝合金
时效强化
显微组织
双峰时效
cast aluminum alloy
age hardening
microstructure morphology
tow-peaks aging
