1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China; 2. Shenzhen Institute of Central South University, Shenzhen 518057, China; 3. CRRC Industrial Research Institute, Beijing 100073, China
Abstract Laser additive repair technologyis of great strategic significance to save cost and improve service performance of materials. In this paper, laser directional energy deposition method was used to study the laser repair of Al-Zn-Mg-Cu aluminum alloy substrate in preset slots. After repairing, the microstructure evolution, metallurgical defects and mechanical properties of Al-Zn-Mg-Cu aluminum alloy were studied by means of scanning electron microscopy, electron backscatter diffraction and universal mechanical testing machine. The results show that the crack is easy to occur when the laser scanning distance increases in repair zone. With the increase of laser energy input, the number of holes in the repair zone increases, and the formation of holes is related to the evaporation of Mg. The Al3(Sc,Zr) particles precipitate in the partial melting zone and the boundary of the molten pool in the repaired zone .The Al3(Sc,Zr) particles play a role of grain refinement. The grain orientation of the zone between the interior and boundary of repair zone is different obviously. The grain orientation of the repaired zone is random while that of the boundary of repair zoneis consistent. Most of the tensile samples fracture in the substrate region that is thermally cycled by the laser. When the scanning rate is 600 mm/min and the scanning spacing is 0.8 mm, the tensile samples fracture in the repaired zone, and there are a certain number of holes in the fracture of the sample.
TANG Haozhou,LI Ruidi,ZHU Hongbin, et al. Microstructure and mechanical property of Al-Zn-Mg-Cu aluminum alloy substrate repaired by laser directed energy deposition with Al-Mg-Sc alloy powder[J]. Materials Science and Engineering of Powder Metallurgy, 2022, 27(1): 111-120.
[1] YANG Z, ZHAO X, TAO W, et al.Comparative study on successive and simultaneous double-sided laser beam welding of AA6056/AA6156 aluminum alloy T-joints for aircraft fuselage panels[J]. International Journal of Advanced Manufacturing Technology, 2018, 97(1/4): 845-856. [2] ZHANG J, SONG B, WEI Q, et al.A review of selective laser melting of aluminum alloys: Processing, microstructure, property and developing trends[J]. Journal of Materials Science & Technology, 2019, 35(2): 270-284. [3] 周旭, 刘祖铭, 黄兰萍, 等. Al-Cu-Mg-Mn-Sc-Zr铝合金的流变行为与热加工图[J]. 粉末冶金材料科学与工程, 2021, 133(4): 372-380. ZHOU Xu, LIU Zuming, HUANG Lanping, et al.Hot deformation behavior and processing map of Al-Cu-Mg-Mn- Sc-Zr aluminium alloy[J]. Materials Science and Engineering of Powder Metallurgy, 2021, 133(4): 372-380. [4] WANG Y, WANG Y T, LI R D, et al.Hall-Petch relationship in selective laser melting additively manufactured metals: Using grain or cell size[J]. Journal of Central South University (English Edition), 2021, 28(4): 1043-1057. [5] CARROLL B E, PALMER T A, BEESE A M.Anisotropic tensile behavior of Ti-6Al-4V components fabricated with directed energy deposition additive manufacturing[J]. Acta Materialia, 2015, 87: 309-320. [6] BRANDL E, PALM F, MICHAILOV V, et al.Mechanical properties of additive manufactured titanium (Ti-6Al-4V) blocks deposited by a solid-state laser and wire[J]. Materials & Design, 2011, 32(10): 4665-4675. [7] 任仲贺, 武美萍, 崔宸, 等. 激光熔覆温度场和CeO2、TiO2对材料相变的影响[J]. 中国激光, 2019, 46(8): 118-125. REN Zhonghe, WU Meipingping, CUI Chen, et al.Effects of temperature field and CeO2, TiO2 on material phase transition in laser cladding[J]. Chinese Journal of Lasers, 2019, 46(8): 118-125. [8] 赖境, 路媛媛, 张航, 等. 低热输入脉冲激光修复高温合金液化裂纹研究[J]. 中国激光, 2019, 46(4): 116-124. LAI Jing, LU Yuanyuan, ZHANG Hang, et al.Liquation cracks in superalloys repaired by low-heat input pulsed laser[J]. Chinese Journal of Lasers, 2019, 46(4): 116-124. [9] 刘丰刚, 林鑫, 宋衎, 等. 激光修复300M钢的组织及力学性能研究[J]. 金属学报, 2017, 53(3): 325-334. LIU Fenggang, LIN Xin, SONG Kan, et al.Microstructure and mechanical properties of laser forming repaired 300M steel[J]. Acta Metallurgica Sinica, 2017, 53(3): 325-334. [10] 熊果, 谢丰伟, 袁紫仁, 等. 激光熔覆无碳Fe-Co-Mo高速钢涂层的组织结构与性能[J]. 粉末冶金材料科学与工程, 2021, 130(1): 84-90. XIONG Guo, XIE Fengwei, YUAN Ziren, et al.Microstructure and properties of carbon-free Fe-Co-Mo high speed steel coating prepared by laser cladding[J]. Materials Science and Engineering of Powder Metallurgy, 2021, 130(1): 84-90. [11] SABOORI A, AVERSA A, MARCHESE G, et al.Application of directed energy deposition-based additive manufacturing in repair[J]. Applied Sciences-Basel, 2019, 9(16): 3316. [12] SINGH A, RAMAKRISHNAN A, BAKER D, et al.Laser metal deposition of nickel coated Al 7050 alloy[J]. Journal of Alloys and Compounds, 2017, 719: 151-158. [13] ZADPOOR A A.Frontiers of additively manufactured metallic materials[J]. Materials, 2018, 11(9): 1566. [14] PENG X, GUO Q, LIANG X, et al.Mechanical properties, corrosion behavior and microstructures of a non-isothermal ageing treated Al-Zn-Mg-Cu alloy[J]. Materials Science and Engineering A, 2017, 688: 146-154. [15] ZHANG Y, JIN S, TRIMBY P W, et al.Dynamic precipitation, segregation and strengthening of an Al-Zn-Mg-Cu alloy (AA7075) processed by high-pressure torsion[J]. Acta Materialia, 2019, 162: 19-32. [16] 林泽桓, 李瑞迪, 祝弘滨, 等. 送粉式激光增材制造Al- Mg-Sc-Zr合金的微观组织与力学性能[J]. 中南大学学报(自然科学版), 2020, 315(11): 3055-3063. LIN Zehuan. LI Ruidi, ZHU Hongbin, et al.Microstructure and mechanical properties of Al-Mg-Sc-Zr alloy by powder feeding laser additive manufacturing[J]. Journal of Central South University (Science and Technology), 2020, 315(11): 3055-3063. [17] 杜刚, 杨文, 闫德胜, 等. 铸态Al-Mg-Sc-Zr合金退火过程中的硬化行为[J]. 金属学报, 2011, 47(3): 311-316. DU Gang, YANG Wen, YAN Desheng, et al.Hardening behavior of the as-cast Al-Mg-Sc-Zr alloy[J]. Acta Metallurgica Sinica, 2011, 47(3): 311-316. [18] 陈琴, 潘清林, 王迎, 等. 微量Sc和Zr对Al-Mg-Mn合金组织与力学性能的影响[J]. 中国有色金属学报, 2012, 22(6): 1555-1563. CHEN Qin, PAN Qinglin, WANG Ying, et al.Effects of minor scandium and zirconium on microstructure and mechanical properties of Al-Mg-Mn alloys[J]. The Chinese Journal of Nonferrous Metals, 2012, 22(6): 1555-1563. [19] ZHANG W, XING Y, JIA Z H, et al.Effect of minor Sc and Zr addition on microstructure and properties of ultra-high strength aluminum alloy[J]. Transactions of Nonferrous Metals Society of China, 2014, 24(12): 3866-3871. [20] LATHABAI S, LLOYD P G.The effect of scandium on the microstructure, mechanical properties and weldability of a cast Al-Mg alloy[J]. Acta Materialia, 2002, 50(17): 4275-4292. [21] ZAKHAROV V V, ROSTOVA T D.Effect of scandium, transition metals, and admixtures on strengthening of aluminum alloys due to decomposition of the solid solution[J]. Metal Science and Heat Treatment, 2007, 49(9/10): 435-442. [22] HARADA Y, DUNAND D C.Microstructure of Al3Sc with ternary transition-metal additions[J]. Materials Science and Engineering A, 2002, 329: 686-695. [23] ZHAO T, DAHMEN M, CAI W, et al.Laser metal deposition for additive manufacturing of AA5024 and nanoparticulate TiC modified AA5024 alloy composites prepared with balling milling process[J]. Optics & Laser Technology, 2020, 131: 106438. [24] ZHANG L, LI X, NIE Z, et al.Comparison of microstructure and mechanical properties of TIG and laser welding joints of a new Al-Zn-Mg-Cu alloy[J]. Materials & Design, 2016, 92: 880-887. [25] 徐力栋. 高强度铝合金焊接结构激光修复接头组织与性能研究[D]. 西安: 西南交通大学, 2018: 27-38. XU Lidong.Study on microstructure and properties of welding joint of laser repair of high-strength aluminum alloy[D]. Xi'an: Southwest Jiaotong University, 2018: 27-38.
2022, Vol. 27 
