中國有色金屬學(xué)報(bào)
ZHONGGUO YOUSEJINSHU XUEBAO
| 第18卷 第11期 總第116期 2008年11月 |
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文章編號(hào)：1004-0609(2008)11-2002-06
Cu-Cr合金低溫時(shí)效析出過程的密度泛函理論
馮 晶1，陳敬超1，肖 冰2，于 杰1， 李 強(qiáng)3，杜曄平1
(1. 稀貴及有色先進(jìn)材料教育部重點(diǎn)實(shí)驗(yàn)室，云南省新材料制備與加工重點(diǎn)實(shí)驗(yàn)室，
昆明理工大學(xué)，昆明 650093；
2. 西安交通大學(xué) 材料科學(xué)與工程學(xué)院，西安 710049
3. 河南理工大學(xué) 材料科學(xué)與工程學(xué)院，焦作454000)
摘 要: 采用霧化法制備過飽和Cu-Cr固溶體，利用透射電鏡觀察過飽和Cu-Cr固溶體低溫時(shí)效富Cr區(qū)的顯微形貌，利用能譜儀分析富集區(qū)Cr元素的含量，計(jì)算形成不同Cr含量富集區(qū)的形成能及合金熵，采用第一原理解釋時(shí)效析出過程中合金富集區(qū)的電子結(jié)構(gòu)變化。結(jié)果表明：隨時(shí)效時(shí)間的增加，Cr不斷在基體中富集，時(shí)效析出是一個(gè)擴(kuò)散遷移過程；富集區(qū)是一種亞穩(wěn)態(tài)，有逐漸向穩(wěn)定態(tài)轉(zhuǎn)變的趨勢，即Cr析出是固溶體能量降低的一種方式。態(tài)密度的計(jì)算證實(shí)，Cr含量56.0%時(shí)富集區(qū)發(fā)生結(jié)構(gòu)轉(zhuǎn)變(出現(xiàn)GP區(qū))，體系內(nèi)原子化學(xué)環(huán)境發(fā)生變化。
關(guān)鍵字: Cu-Cr合金；時(shí)效；熱力學(xué)性質(zhì)；第一原理
Density functional theory of Cu-Cr alloy during aging precipitation process at low temperature
FENG Jing1, CHEN Jing-chao1, XIAO Bing2, YU Jie1, LI Qiang3, DU Ye-ping1
（1. Key Laboratory of Advanced Materials of Precious-Nonferrous Metals, Education Ministry of China,
Key Laboratory of Advanced Materials of Yunnan Province, Kunming University of Science and Technology, Kunming 650093, China;
2. School of Materials Science and Engineering，Xi’an Jiaotong University, Xi’an 710049, China;
3. School of Materials Science and Engineering, Henan University of Technology, Jiaozuo 454000, China）
Abstract:Supersaturated Cu-Cr solid solution was prepared by atomization. The microstructures of Cr rich zone in Cu-Cr solid solution were investigated by transmission electron microscopy and electron energy disperse spectroscopy. The formation energy and entropy of different Cr soluble enrichment districts were calculated. The electric structure changes of richment zones during aging precipitation process were explained by the first principle. The mechanism of aging precipitation was explained. The results show that the GP zone is presented at relatively low temperature, the concentration of Cr also increases due to the soluble enrichment process. The soluble enrichment is a metastable phase and declines the system energy. The structure of enrichment zones with 56%Cr is transformed and the environment of atoms in GP zone is charged too.
Key words: Cu-Cr alloy; aging; thermodynamic property; first principle
