(1. 東北大學(xué)材料與冶金學(xué)院，沈陽 110819；
2. 上海空間推進(jìn)研究所，上海201112；
3. 東北大學(xué)材料各向異性與織構(gòu)教育部重點(diǎn)實(shí)驗(yàn)室，沈陽 110819)
摘 要: 研究溫度、保溫時(shí)間及拉伸速度對(duì)半連續(xù)鑄造Al-13.7Si合金高溫力學(xué)性能和顯微組織的影響。結(jié)果表明：半連續(xù)鑄造Al-13.7Si合金在450℃拉伸時(shí)伸長率達(dá)到85.34%；Al-13.7Si合金表現(xiàn)出較高的高溫塑性主要是由整個(gè)鋁基體向細(xì)化的等軸晶轉(zhuǎn)變引起的；Al-13.7Si合金適宜的熱變形溫度為450~500 ℃；當(dāng)熱變形溫度高于450 ℃時(shí)，隨著溫度的升高或保溫時(shí)間的延長，合金的伸長率和抗拉強(qiáng)度均呈下降趨勢；隨著拉伸速度的降低，各溫度下合金的抗拉強(qiáng)度下降，而伸長率呈上升趨勢。
關(guān)鍵字: 鋁硅合金；高溫力學(xué)性能；組織演變；過共晶
（1. School of Materials and Metallurgy, Northeastern University, Shenyang 110819, China;
2. Shanghai Institute of Space Propulsion, Shanghai 201112, China;
3. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education,
Northeastern University, Shenyang 110819, China）
Abstract:The high-temperature mechanical properties and microstructure of DC cast hypereutectic Al-13.7Si alloy were investigated at different temperatures, holding time and tensile velocities. The results show that the elongation of Al-13.7Si alloy is 85.43% at 450℃. Excellent ductility of the studied alloy at high temperature is due to the transformation of fine equiaxed grains in the whole Al matrix. The suitable hot deformed temperature of Al-13.7Si alloy is from 450 ℃ to 500 ℃. When the temperature of tensile is higher than 450 ℃, with increasing the temperature or prolonging the holding time, the elongation and tensile strength of the Al-13.7Si alloy decrease. With decreasing the tensile velocity, the tensile strength decreases while the elongation of the Al-13.7Si alloy increases.
Key words: Al-Si alloy; high temperature mechanical property; microstructure evolution; hypereutectic
