(1. 西安交通大學(xué) 材料科學(xué)與工程學(xué)院, 金屬材料強(qiáng)度國(guó)家重點(diǎn)實(shí)驗(yàn)室, 西安 710049;
2. 中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室, 長(zhǎng)沙 410083)
摘 要: 電導(dǎo)率的變化能夠靈敏地反應(yīng)Al-Mg-Si合金的時(shí)效析出過程，然而溶質(zhì)原子及時(shí)效析出第二相對(duì)電導(dǎo)率的單獨(dú)影響尚不清楚。Al-Mg-Si合金中含有3種成分和形貌不同的第二相。通過實(shí)驗(yàn)及模型化系統(tǒng)地研究Al-Mg-Si合金中多重析出第二相對(duì)其電導(dǎo)率的影響。結(jié)果表明：由于棒狀β′′相或針狀β′相能夠分別在473和523 K時(shí)有效地阻礙傳導(dǎo)電子的移動(dòng)，因此Al-Mg-Si合金的電導(dǎo)率主要依賴于棒狀β′′相(T=473 K)或針狀β′相(T=523 K)的影響。模型預(yù)測(cè)結(jié)果與實(shí)驗(yàn)結(jié)果吻合良好，驗(yàn)證了模型的有效性。
關(guān)鍵字: Al-Mg-Si合金；多重析出；電導(dǎo)率
aged Al-Mg-Si alloys
（1. State Key Laboratory for Mechanical Behavior of Materials, School of Material Science & Engineering,
Xi’an Jiaotong University, Xi’an 710049, China;
2. State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The electrical conductivity measurement is a much sensitive tool for studying the precipitation in Al-Mg-Si alloys, but the single effects of solute atoms and fine scale precipitates on electrical conductivity are not clear. In this work, the systematic experiments and modeling were performed to study the effect of multiple precipitates on the electrical conductivity of aged Al-Mg-Si alloys that contain three kinds of precipitates with different compositions and morphologies. The results show that the electrical conductivity of the alloy exhibits the most sensitive to a dominant kind of precipitates, i.e., rod-shaped β′′ precipitates at 473 K and needle-shaped β′ precipitates at 523 K, respectively. This is because the two kinds of precipitates can form an effective barrier net to hinder the mass migration at 473 and 523 K, respectively. The good agreement between model and experiments indicates the validity of prediction.
Key words: Al-Mg-Si alloys; multiple precipitates; electrical conductivity
