同步送粉水下激光增材铁基合金凝固组织演变与温度场研究  

Solidification Structure Evolution and Temperature Field Study of Iron-based Alloys with Synchronous Powder-feeding Underwater Laser Additive

作　　者：刘伊 娄丽艳[2] 刘康诚 李成新[1] LIU Yi;LOU Liyan;LIU Kangcheng;LI Chengxin(State Key Laboratory of Metal Material Strength,Xi′an Jiaotong University,Xi′an 710049,China;National Local Joint Engineering Laboratory of Intelligent Manufacturing Technology for Automotive Molds,Tianjin Vocational and Technical Normal University,Tianjin 300222,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049 [2]天津职业技术师范大学汽车模具智能制造技术国家地方联合工程实验室,天津300222

出　　处：《有色金属工程》2024年第12期1-10,I0002,共11页Nonferrous Metals Engineering

基　　金：天津市自然科学基金项目(22JCYBJC01650)。

摘　　要：针对海洋环境中大量存在的铁基结构材料表面损伤修复与水下原位再制造的需求,通过层状累加成型的方法,实现了同轴送粉式水下激光增材制造(SUAM)技术。由于多次热量输入时温度梯度的不稳定性,增材结构上部的晶粒生长与平面涂层相似,靠近基体的区域没有明显的柱状晶粒。EBSD结果表明,晶粒大小和位错密度在增材叠加界面发生了变化,出现外延生长现象,在块体中间出现了一个周期性细晶粒带,细晶粒带的平均硬度为805 HV 0.025,而较大的等轴晶粒区的硬度为770 HV 0.025。进一步通过引入保护气流和沸腾模型,利用数值模拟获得了SUAM激光加热过程的温度场。水下激光加热最高温度比空气中低约16%,且沸腾模型不会影响温度分布。研究为进一步实现SUAM提供了理论支持。To address the requirements for surface damage repair and underwater in-situ remanufacturing of iron-based structural materials prevalent in the marine environment,this paper implemented a coaxial powder-feeding submerged laser additive manufacturing(SUAM)technology using a layer-by-layer molding method.Due to the unstable temperature gradients from multiple heat inputs,the grain growth in the upper region of the additive structure resembles that of a planar coating,with no distinct columnar grains in the region close to the substrate.EBSD results show that the grain size and dislocation density changed between the additive interface,and epitaxial growth phenomenon occurs,and a periodic fine-grained band appears in the middle of the block,and the average hardness of the fine-grained band is 805 HV 0.025,while the hardness of the larger equiaxed grain zone is 770 HV 0.025.Further the temperature field of the SUAM laser heating process was obtained using numerical simulations by introducing a protective air and boiling model.The maximum temperature of underwater laser heating is about 16%lower than that in air,and the boiling model has no effect on the temperature distribution.This study provides theoretical support for for advancing the development and application of SUAM.

关 键 词：激光增材 水下原位制造 凝固组织 数值模拟 

分 类 号：TG132[一般工业技术—材料科学与工程] TG178[金属学及工艺—合金]