摘要
通过显微组织观察和力学性能与电导率测试,研究了热处理工艺对7B04铝合金厚板组织与性能的影响。结果表明,适宜的固溶工艺为470℃×240min。120℃×22h时效后合金可获得,抗拉强度为621MPa,但合金的电导率较低,仅为18·3MS/m;双级T74时效时,强度下降了10%～12%(与T6态相比),电导率获得了明显提高,为21·3MS/m;三级时效(RRA)处理可使合金获得高强度和高电导率相结合,强度接近T6态,电导率与T74态相当。合金经RRA处理后,基体内分布着大量的细小弥散析出相(与T6态组织相似),晶界析出相粗大且呈完全不连续分布。
Effects of heat treatment on microstructures and properties of 7B04 aluminum alloy thick plates have been investigated by optical microscope and transmission electron microscope,tensile testing and electrical conductivity testing.The results show that the optimal solid solution is treated at 470 ℃ for 240 min.Maximum tensile strength of 621 MPa can be observed with lower electric conductivity only 18.3 MS/m,after aged at 120 ℃ for 22 h.Although the tensile strength of the alloy is decreased by 10%~12%,compared with that of T6 treated alloy,the electric conductivity is evidently improved by 21.3 MS/m after two-step T74 aging treatment.The high strength and high electric conductivity can be observed by RPA treatment,equivalent to T6 alloys in strength and to T4 alloy in electric conductivity.Amounts of fine disperoids are distributed into the RPA alloy with coarse and fully discontinuously distributed precipitation phase from the boundary.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2007年第6期427-430,共4页
Special Casting & Nonferrous Alloys
基金
国家高技术研究发展计划(863计划)资助项目(2003AA331100)
关键词
7B04铝合金
固溶
时效
组织
力学性能
7B04 Aluminum Alloy,Solid Solution,Aging,Microstructure,Mechanical Properties
