Transactions of Nonferrous Metals Society of China The Chinese Journal of Nonferrous Metals

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中国有色金属学报

ZHONGGUO YOUSEJINSHU XUEBAO

第20卷    第7期    总第136期    2010年7月

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文章编号:1004-0609(2010)07-1290-06
电场对2E12铝合金中S相析出动力学的影响
周明哲1, 易丹青1, 2, 尹德艳1, 洪天然1, 黄道远1

(1.中南大学 材料科学与工程学院,长沙 410083;
2. 中南大学 教育部有色金属材料科学与工程重点实验室,长沙 410083
)

摘 要: 采用示差扫描量热法(DSC),研究2E12铝合金在190 ℃时效过程中施加强电场(±9 kV/cm)对合金析出的动力学的影响,并探讨电场影响合金时效过程的微观机理。结果表明:时效时施加强电场促进了合金中Ⅰ型S相向Ⅱ型S相的转变,使得析出峰提前;未施加电场的合金样品具有更高的过饱和度、析出焓、析出相体积分数及析出速率;强电场作用降低合金中空位与溶质原子之间的结合能,进而降低S相析出激活能。根据DSC结果对S相析出激活能进行Kissinger方法和普适积分法计算发现,时效过程中施加电场与未施加电场相比,S相激活能分别降低7.9~12.7 kJ/mol和6.8~22.6 kJ/mol。

 

关键词: 2E12铝合金;S相;电场;时效;示差扫描量热法;动力学

Effect of electric field on kinetics of formation of S phase in2E12 aluminum alloy
ZHOU Ming-zhe1, YI Dan-qing1, 2, YIN De-yan1, HONG Tian-ran1, HUANG Dao-yuan1

1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China

Abstract:The influence of electric field (±9 kV/cm) on the aging kinetics and mechanism of 2E12 aluminum alloy during aging at 190 ℃ were investigated by differential scanning calorimetry (DSC). The results show that the transformation of S phase from type Ⅰ to type Ⅱ is promoted by applying electric field. The S phase formation peak in DSC curves under electric field shifts to a lower temperature. The supersaturation degree, formation enthalpy, volume fraction of precipitates and precipitation rate of aged alloy without electric field are higher than those with electric field. The bonding energy between the vacancy and solute atom is decreased by introducing electric field, causing lower activation energies of S phase formation. Based on the DSC results, the activation energies of S phases with electric field in aging are 7.9 −12.7 kJ/mol and 6.8−22.6 kJ/mol lower than those without electric field calculated by the method of Kissinger and general integration measurement, respectively.

 

Key words: 2E12 aluminum alloy; S phase; electric field; aging; differential scanning calorimetry; kinetics

ISSN 1004-0609
CN 43-1238/TG
CODEN: ZYJXFK

ISSN 1003-6326
CN 43-1239/TG
CODEN: TNMCEW

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