(1.蘭州理工大學(xué)省部共建有色金屬先進(jìn)加工與再利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050；
2.蘭州理工大學(xué)有色金屬合金及加工教育部重點(diǎn)實(shí)驗(yàn)室，蘭州 730050)
摘 要: 以AlSi10MnMg鋁硅合金為基礎(chǔ)，研究微量Sr+Ce復(fù)合變質(zhì)對(duì)AlSi10MnMg合金顯微組織、導(dǎo)熱性能及力學(xué)性能的影響。結(jié)果表明：在金屬型鑄造條件下，Sr、Ce的添加有效改善了AlSi10MnMg合金中共晶Si形貌，降低了Si相尺寸，提高了Si相圓整度，進(jìn)而提升了合金導(dǎo)熱率及力學(xué)性能。添加0.05%Sr+0.02%Ce (質(zhì)量分?jǐn)?shù))時(shí)合金變質(zhì)效果最優(yōu)，與未變質(zhì)的AlSi10MnMg合金相比，其導(dǎo)熱率提升了14.86%，達(dá)到181.68W/(m·K)；抗拉強(qiáng)度提升了42.4%，達(dá)到228.94MPa；伸長(zhǎng)率提升了101.5%，達(dá)到14.62%，實(shí)現(xiàn)了導(dǎo)熱性能與力學(xué)性能的良好結(jié)合。而當(dāng)稀土元素Ce添加量超過(guò)0.04%(質(zhì)量分?jǐn)?shù))后，合金的導(dǎo)熱率及力學(xué)性能呈降低趨勢(shì)。針對(duì)復(fù)合變質(zhì)后合金中可能出現(xiàn)的金屬間化合物進(jìn)行建模、優(yōu)化，并采用第一性原理和Cahill模型對(duì)其導(dǎo)熱率進(jìn)行計(jì)算，研究發(fā)現(xiàn)Sr+Ce復(fù)合變質(zhì)后，合金中出現(xiàn)的Sr-RE金屬間化合物會(huì)降低AlSi10MnMg合金的導(dǎo)熱性及力學(xué)性能。
關(guān)鍵字: AlSi10MnMg鋁合金；Sr+Ce復(fù)合變質(zhì)；導(dǎo)熱率；力學(xué)性能；第一性原理
（1.State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology, Lanzhou 730050, China;
2. Key Laboratory of Non-ferrous Metal Alloys and Processing, Ministry of Education,Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:Based on AlSi10MnMg Al-Si alloy, the effects of Sr+Ce compound modification on microstructure, thermal conductivity and mechanical properties of AlSi10MnMg alloy were studied. The results show that the addition of Sr and Ce can effectively improve the morphology and decrease the size and roundness of eutectic Si, and improve the thermal conductivity and mechanical properties of AlSi10MnMg alloy. Compared with the unmodified AlSi10MnMg alloy, the thermal conductivity of the alloy increases by 14.86% to 181.68W/(m·K), the tensile strength increases by 42.4% to 228.94 MPa, and the elongation increases by 101.5% to 14.62%, the combination of thermal conductivity and mechanical properties is realized. However, when the rare-earth element Ce exceeds 0.04% (mass fraction), the thermal conductivity and Mechanical properties of the alloy decrease. Based on the modeling and optimization of the intermetallic compounds that may appear in the alloy after the composite modification, the first-principles and Cahill model are used to calculate the thermal conductivity. It is found that the Sr-RE intermetallic compounds in the alloy after the Sr+Ce composite modification can reduce the thermal conductivity and mechanical properties of AlSi10MnMg alloy.
Key words: AlSi10MnMg aluminum alloy; Sr+Ce compound modification; thermal conductivity; mechanical property; first-principle
