热处理对激光增材ATI 718Plus的组织与力学性能的影响  

Effects of Heat Treatment on Microstructure and Mechanical Property of ATI 718Plus by Laser Additive Manufacturing

作　　者：任逸群 吴悦晨 常帅[1] 李俐群[1] 王民庆[2] Ren Yiqun;Wu Yuechen;Chang Shuai;Li Liqun;Wang Minqing(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,Heilongjiang,China;Central Iron&Steel Research Institute,Beijing 10008l,China)

机构地区：[1]哈尔滨工业大学材料结构精密焊接与连接全国重点实验室,黑龙江哈尔滨150001 [2]钢铁研究总院,北京100081

出　　处：《中国激光》2024年第16期202-210,共9页Chinese Journal of Lasers

基　　金：国家科技重大专项(J2019-Ⅶ-0004-0144)。

摘　　要：使用激光熔化沉积技术制备了ATI 718Plus薄壁单墙样品,研究了不同热处理工艺对沉积单墙组织及力学性能的影响。沉积态组织主要呈现外延生长的柱状树枝晶形貌,枝晶间析出了大量Laves相,该相消耗了大量Nb、Mo等合金强化元素。试验发现热处理工艺对样品组织有着显著影响。直接时效热处理后,Laves未发生明显溶解,但周围析出了大量η相;982℃固溶时效热处理后,Laves相由长链状变为颗粒状,有部分再结晶发生;而1020℃固溶时效热处理后,Laves相基本溶解,再结晶现象显著,柱状晶转变为等轴晶。室温拉伸结果表明,合适的热处理可以减少Laves相,从而提高沉积样品的强度和塑性。其中直接时效热处理的强度最高,相比沉积态抗拉强度提高了51.9%,但断后伸长率下降了13%。1020℃固溶时效热处理的综合性能最好,相比沉积态抗拉强度提高了34.2%,断后伸长率提高了25.8%。Objective Laser melting deposition is used to prepare ATI 718Plus samples to study the effects of three heat treatment regimes on their microstructure evolution,hardness,and room temperature tensile properties.These regimes include direct aging heat treatment,solutionizing and aging heat treatment at 982℃,and high-temperature solutionizing and aging heat treatment at 1020℃.The aim is to elucidate the phase transformation behavior and mechanical property changes of laser additive ATI 718Plus under different heat treatment regimes and provide guidance for the selection of heat treatment processes used in the laser additive manufacturing of ATI 718Plus.Methods The plasma rotating electrode process is used with ATI 718Plus powder with particle diameter of 45-105μm to prepare wrought ATI 718Plus superalloy substrates.The experiments are performed on the laser additive manufacturing system shown in Fig.2,which consists of a 4000 W continuous wave fiber laser,an inert atmosphere processing chamber,a coaxial nozzle,and a powder feeding device.A well-formed ATI 718Plus sample is prepared using a unidirectional reciprocating scanning method with the following parameters:a laser power of 1200 W,scanning speed of 0.8 m/min,protective gas flow rate of 10 L/min,carrier gas flow rate of 15 L/min,and powder feed rate of 13 g/min.The geometric dimensions of each sample are 50.0 mm×58.0 mm×2.5 mm.Three heat treatment regimes are employed,as shown in Fig.2(b).The analyzed samples are mechanically ground with SiC paper and polished using diamond suspensions and a colloidal silica suspension to prepare metallographic samples.Then,the polished samples are etched with No.2 waterless Kailing?s reagent for optical microscope and scanning electron microscope(SEM)investigations.Uniaxial tensile tests are carried out at room temperature using a universal testing machine with a constant displacement rate of 1 mm/min.Results and Discussions After laser deposition,a large number of Laves phase areas form in the interdendritic region(Fig

关 键 词：激光技术 激光熔化沉积 镍基高温合金 热处理 

分 类 号：TG456.7[金属学及工艺—焊接]