对铸态L2纯铝分别进行了单道次和2,3次重复搅拌摩擦加工处理,研究了搅拌摩擦加工次数对L2纯铝组织性能的影响。结果表明:剧烈的塑性变形促使粗大的枝状晶显著破碎,形成了细小且均匀分布的再结晶组织,重复加工次数对再结晶晶粒的尺寸影响较小。重复搅拌摩擦加工后,铸态L2纯铝的最大显微硬度值提高了17 HV,最大抗拉强度及延伸率分别提高了39 MPa和22%,试样的拉伸断口呈现出微孔聚合韧性断裂特征。随着重复加工次数的增加,相邻道次间的显微硬度、抗拉强度和延伸率差值均减小。
Abstract
Single pass,2-pass and 3-pass of friction stir processing(FSP) were conducted on cast pure aluminum L2.Effect of FSP times on microstructure and properties of cast pure aluminum L2 was studied.The results show that intense plastic deformation results in significant breakup of the coarse dendrites and creates a fine,uniform recrystallized microstructure;accumulative processing times have a little effect on the size of recrystallized grain.The highest microhardness,ultimate tensile strength and elongation increase by 17 HV,39 MPa and 22%,respectively after accumulation of FSP;the surface fracture of the FSPed tensile specimens exhibit a typical ductile dimple-fracture.The differences of microhardness,ultimate tensile strength and elongation between adjacent passes are reduced with more accumulative processing times.
关键词
重复搅拌摩擦加工 /
铸态L2纯铝 /
组织性能 /
细晶强化
{{custom_keyword}} /
Key words
accumulation of fric /
cast pure aluminum L /
microstructure and p /
fine-grained strengt
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
THOMAS W M,NEEDLHAM J C,DAWES C J,et al.Friction stir butt welding[P].Intenational patent application number PCT/GB92/02203 and GB patent application 9125978.8,1991-12-06.
MISHRA R S,MAHONEY M W,MCFADDEN S X,et al.High strain rate superplasticity in a friction stir processed 7075Al alloy[J].Scripta Materialia,2000,42:163-168.
MISHRA R S,MA Z Y.Friction stir welding and processing[J].Materials Science and Engineering R,2005,50:1-78.
孙鹏,王快社,王文,等.工艺参数对AZ31镁合金搅拌摩擦加工微观组织的影响[J].热加工工艺,2008,37(5):99-101.
王快社,王文,孙鹏,等.搅拌摩擦加工镁合金摩擦磨损性能研究[J].润滑与密封,2008,33(11):16-19.
SANTELLA M L,ENGSTROM T,STORJOHANN D,et al.Effects of friction stir processing on mechanical properties of the cast aluminum alloys A319 and A356[J].Scripta Materialia,2005,53:201-206.
NAKATA K,KIM Y G,FUJII H,et al.Improvement of mechanical properties of aluminum die casting alloy by multi-pass friction stir processing[J].Materials Science and Engineering A,2006,437:274-280.
陈振华.变形镁合金[M].北京:化学工业出版社,2005:160-166.
朱战民,陈体军,申雄飞,等.搅拌摩擦加工次数对AZ91D镁合金组织的影响[J].机械工程材料,2007,31(7):8-10.
崔忠圻.金属学与热处理[M].北京:机械工业出版社,2003:179-181.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
基金
国家自然科学基金资助项目(50774059);西安建筑科技大学材料加工工程重点学科建设资助项目(E04001)
{{custom_fund}}
PDF(539 KB)
({{custom_author.role_cn}}), {{javascript:window.custom_author_cn_index++;}}
