大连理工_江苏大学增材顶刊..._MPa铝合金复合增材制造.pdf

um deformed to high strain and annealedJ.Acta Materialia，2009，57（14）：4198-4208.14 Grabski M W.The Hall-Petch relation in aluminium and itsdependence on the grain boundary structureJ.Philosophical Magazine A，1986，53（4）：505-520.15 SU L H，LU C，TIEU A K，et al.Vacancy-assisted hardeninginnanostructuredmetalsJ.MaterialsLetters，2011，65（3）：514-516.Effect of external electric field heat treatment on microstructure andproperties of equal diameter angular extrusion 1050 aluminum alloySun Keming2,Yu Liming1,Qian Weitao1(1.Tangshan Normal University,Ocean College,Tangshan 063000;2.School of Materials Science and Engineering,Tianjin University,Tianjin 300072,China）Abstract:In this paper,experimental methods such as EBSD test,tensile test and PALS test were used to study the thermal dynamicsand microstructure characteristics of 1050 aluminum alloy under constant diameter angular extrusion at low temperature.After annealing at different temperatures(150400)with current and without current,the differences between thermal dynamics and microstructure characteristics of 1050 aluminum alloy were compared.On the basis of the experimental results,the effect mechanism of differentannealing temperature on the microstructure and properties of the materials was discussed.The results show that when the annealingtemperature is 150250,the yield strength of the sample with applied current decreases by 8.1%11.2%compared with that withoutapplied current.As a result,the grain boundary structure with large orientation Angle of 37accounts for a larger proportion,the internal energy increases,and the internal structure of the grain boundary with large orientation Angle is unstable.At 300400,theyield hardness of samples annealed without DC is decreased more significantly and faster than that annealed with DC.The grain size ofsamples annealed without DC is also increased rapidly to(6.422.4m).The grain length of the sample is smaller than that of the sample without direct current,so the yield strength is higher.Key words:electric field;aluminum alloy;heat treatment;microstructure and properties大连理工&江苏大学增材顶刊：新方法！实现600 MPa铝合金复合增材制造由于Al-Zn-Mg-Cu合金较大的凝固区间（约150 K），热膨胀系数高，开裂敏感性大，熔体流动性差，导热系数高等特性，在采用激光粉末床熔化技术（LPBF）快速熔凝过程中易出现热裂纹；采用电弧增材制造（WAAM）时电弧的热输入较大，熔池的凝固速率较小，看上去能够解决Al-Zn-Mg-Cu合金LPBF过程易生裂纹的制造难题，遗憾的是，WAAM过程的高热输入同样会促进粗大晶粒、气孔以及元素偏析的形成，这将导致性能的各向异性和拉伸强度的降低。基于此，大连理工大学机械工程学院马广义、吴东江教授与江苏大学鲁金忠、罗开玉教授合作，提出激光-电弧复合增材制造新方法，解决Al-Zn-Mg-Cu合金的增材制造难题，相关论文以题为“Superior strength of laser-arc hybrid additivemanufactured Al-Zn-Mg-Cu alloy enabled by a tunable microstructure”，发表在增材制造顶级期刊 Additive Manufacturing上。该技术采用定域可控的脉冲激光作为热源之一，与热输入较大的电弧复合共同熔化焊丝，通过激光与电弧的协同作用，制备出Al-Zn-Mg-Cu合金样件。研究了激光-电弧复合增材过程微观组织的形成机制，以及随后的固溶+时效热处理对组织和力学行为的影响。孙克明，等：外加电场热处理对等径角挤压态1050铝合金组织与性能的影响组织性能/信息报道 24