采用粉末热挤压法制备了一种Al-Zn-Mg-Cu超高强铝合金,研究了粉末粒度和挤压比对合金组织和力学性能的影响.结果表明,400℃挤压时,粉末中位径D50=28.38μm和挤压比λ=25可使挤压合金获得最好的力学性能,挤压合金经过460℃/2.5h水淬+120℃/24h空冷(T6)处理后的抗拉强度、屈服强度和伸长率分别为731MPa,670MPa和6.2%;晶粒细化是挤压合金力学性能随粉末粒度减小而提高的原因;挤压比λ为9~25时,挤压合金力学性能随挤压比增大而提高;λ=36时,挤压合金力学性能降低的原因是MgZn2析出相粗大和发生完全动态再结晶.
Abstract
In this study,an Al+Zn-Mg-Cu ultra strength aluminium alloy was fabricated by powder hot extrusion process,and the effects of powder granularity and extrusion ratio on microstructures and mechanical properties of alloys were investigated.The results show that the optimal powder median size(D50) for the consolidation of alloyed powder is 28.38μm,and the extrusion ratio(λ) is 25.By extrusion at 400℃,the best mechanical properties were obtained with the above as-optimized processing parameters.After T6 temper,i.e.460℃×2.5h water quenching+120℃×24h air cooling,the tensile strength,yield strength and elongation of the heat treated alloy are 731MPa,670MPa and 6.2%,respectively.The mechanical properties of extruded alloys increasing with the decrease of powder granularity are due to grain refinement.The mechanical properties of extruded alloys increase with the increase of extrusion ratio from 9 to 25.Coarse MgZn2 precipitated phases and complete dynamic recrystallization lead to the reducing of mechanical properties of the extruded alloy produced by extrusion ratio 36.
关键词
粉末热挤压 /
Al-Zn-Mg-Cu合金 /
显微组织 /
力学性能 /
动态再结晶
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Key words
powder hot extrusion /
Al+Zn-Mg-Cu aluminum /
microstructure /
mechanical propertie /
dynamic recrystalliz
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参考文献
潘复生,张丁非.铝合金及应用[M].北京:化学工业出版社,2006.
吴一雷,李永伟,强俊,等.超高强度铝合金的发展与应用[J].航空材料学报,1994,14(1):49-55.
AZARI H N,MURTY G S,UPADHYAYA G S.Superplastic behavior of thermomechanically treated P/M 7091 aluminum alloy[J].Metallurgical and Materials Transactions(A),1994,25:2153-2160.
PICKENS J R,PRECHT W,WESTWOOD A R C.Embrittlement of P/M X7091 and I/M 7175 aluminium alloys by mercury solutions[J].Journal of Materials Science,1983,18:1872-1880.
PICKENS J R.Review Aluminium powder metallurgy technology for high-strength application[J].Journal of Materials Science,1981,16:1437-1457.
RAO V V.Centrifugal atomization and rapid-solidification processing of high-strength aluminium alloys[J].Journal of Materials Science Letters,1992,11:135-137.
陈振华,陈鼎.快速凝固粉末铝合金[M].北京:冶金工业出版社,2009.
LI Yuan-yuan,ZHANG Da-tong,XIA Wei,et al.Study on the extruded structure of rapidly solidioed hypereutectic Al-Si alloys[J].Journal of Materials Science Letters,2002,21:537-538.
杨伏良,甘卫平,陈招科,等.快速凝固/粉末冶金制备高硅铝合金材料的组织与力学性能[J].中国有色金属学报,2004,14(10):1717-1722.
GUO J Q,KITA K,KAZAMA N S,et al.Mechanical properties,microstructure and crystal structures of A198-3x Cu-(2x)Fex Ce-l Zr-l(x =1-3 at.%)alloys extruded from their atomized powders[J].Materials Science and Engineering A,1995,203:420-426.
GUO J Q,KAZAMA N S.Mechanical properties of rapidly solidified Al-Ti-Fe,Al-Cu-Fe and Al-Fe-Cu-Ti based alloys extruded from their atomized powders[J].Materials Science and Engineering A,1997,232:177-182.
KAWAMURAL Y,INOUEL A,TAKAGI M,et al.Rapidly solidified powder metallurgy of Al-Ti-Fe-X Alloys[J].Scripta Materialia,1999,40(10):1131-1137.
ВАЙНБЛАТЮМ,ШАРШАГИННА,ЦВЕТНЫЕ,et al.铝合金的动态再结晶[J].洪永先译.轻合金加工技术,1984,(12):32-35.
PATLAN V,VINOGRADOV A,HIGASHI K,et al.Overview of fatigue properties of fine grain 5056 Al-Mg alloy processed by equal-channel angular pressing[J].Materials Science and Engineering A,2001,300:171-182.
张胜华,胡泽豪,朱旭霞,等.LY12CZ挤压棒材粗晶环微观分析[J].中国有色金属学报,1996,6(3):123-126.
毛卫民,赵新兵.金属的再结晶与晶粒长大[M].北京:冶金工业出版社,1994.
ZHOU Jian,ZHANG Ting-jie,ZHANG Xiao-ming,et al.The influence of strain rate and solution treatment on dynamic recrystallization for 7075 aluminum alloy[J].Rare Metal Materials and Engineering,2004,33(6):580-584.
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