预回复对Al-13.0Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr铝合金挤压材在T652态组织与性能的影响  

Effect of pre-recovery treatment on microstructure and properties of extruded Al-13.0Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr aluminum alloy

作　　者：孙良省 许晓静[1] 蒋伟[1] 范亚洲[1] 

机构地区：[1]江苏大学先进制造与现代装备技术工程研究院,江苏镇江212013

出　　处：《材料热处理学报》2015年第12期61-66,共6页Transactions of Materials and Heat Treatment

基　　金：江苏省工业科技支撑计划项目(BE2008118);江苏大学"拔尖人才培养工程基金"(1211110001);江苏省高校研究生科研创新计划项目(CXLX12_0620);江苏省优势学科资助

摘　　要：采用X射线衍射分析(XRD)、电子背散射衍射分析(EBSD)、电导率测试、硬度测试、拉伸试验、晶间腐蚀试验和剥落腐蚀试验,研究了固溶处理前的预回复处理(250℃×24 h+300℃×6 h+350℃×6 h+400℃×6 h)对高合金化铝合金Al-13.0Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr挤压材在T652态组织与性能的影响。结果表明,固溶前的预回复处理降低了位错密度,减小了平均晶粒尺寸(8.764μm vs.4.835μm)和平均晶界角度,显著提高了低角度晶界数目分数(0.410 vs.0.658)和电导率(24.6%ICAS vs.26.3%ICAS),降低了硬度(228.2 HV vs.227.0 HV)、屈服强度(680.3 MPa vs.662.5 MPa)、抗拉强度(714.5 MPa vs.695.5 MPa)和伸长率(7.6%vs.5.6%),提高了抗晶间腐蚀和抗剥落腐蚀性能;定量分析显示,预回复处理轻微降低了合金位错强化、低角度晶界强化和高角度晶界强化的总强化,合金强度的降低主要归因于合金固溶强化和时效沉淀析出相强化的总强化的降低;抗腐蚀性能的提高可以归因于合金低角度晶界数目百分比的提高。Effects of pre-recovery treatment（ 250 ℃ × 24 h ＋ 300 ℃ × 6 h ＋ 350 ℃ × 6 h ＋ 400 ℃ × 6 h） prior to solid solution on microstructures and properties of extruded Al-13. 0Zn-3. 16Mg-2. 8Cu-0. 2Zr-0. 07 Sr alloy under T652 state were investigated by XRD and EBSD analyses,and electric conductivity,hardness,tensile,inter-granular corrosion and exfoliation corrosion tests. The results show that the pre-recovery treatment decreases the dislocation density,average grain size and average grain boundary angles,improves the proportion of low angle grain boundary and electric conductivity considerably,decreases the hardness,yield strength,ultimate tensile strength and elongation,and raises the intergranular corrosion and exfoliation corrosion resistance. Quantitative analysis demonstrates that the pre-recovery treatment has slight influence on the sum of dislocation strengthening,low angle grain boundary strengthening and high angle grain boundary strengthening. The decrease of strength can be attributed to the decline of the sum of solid solution strengthening and aging precipitated phase strengthening. The improvment of corrosion resistance is due to the increase of the proportion of low angle grain boundaries.

关 键 词：AL-ZN-MG-CU铝合金 预回复处理 强化机理 组织性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]