柴鹏涛,刘学,李晋锋,刘政豪,杨晓珊,周昱昭,王小英,董鲜峰,乐国敏.超声振动辅助激光熔化沉积316L不锈钢的微观组织演变研究[J].稀有金属材料与工程,2020,49(12):4177~4184.[Chai Pengtao,Liu Xue,Li Jinfeng,Liu Zhenghao,Yang Xiaoshan,Zhou Yuzhao,Wang Xiaoying,Dong Xianfeng,Le Guomin.Microstructural Evolutions of 316L Stainless Steel Prepared by Ultrasonic Vibration Assisted Laser Melting Deposition[J].Rare Metal Materials and Engineering,2020,49(12):4177~4184.]
超声振动辅助激光熔化沉积316L不锈钢的微观组织演变研究
投稿时间:2019-12-25  修订日期:2020-04-09
中文关键词:  超声振动  激光熔化沉积  316L不锈钢  晶粒形态  晶粒尺寸  凝固方式
基金项目:国家重点研发计划(2017YFB0702400);国家自然科学基金资助(项目号51871203,11605164)
中文摘要:
      在激光熔化沉积316L不锈钢的过程中耦合不同功率的超声振动,研究了超声功率对晶粒形态尺寸、凝固组织形成机制以及晶粒生长特性的影响。研究表明,激光熔化沉积过程中316L不锈钢晶粒发生定向凝固外延生长,形成粗大的柱状晶。施加超声会将沿[100]方向外延生长的粗大原生柱状晶打碎,产生细化晶粒的效果;沿柱状晶外延生长方向传递的超声振动增大了晶粒内沿长轴方向的累积取向差,提高了平均位错密度。施加超声有助于加强熔池流体的对流,降低沿沉积方向的温度梯度,使得垂直生长的柱状晶更快转变为八字形柱状晶;同时提高合金凝固冷速,使得柱状晶宽度以及晶粒内部一次枝晶列间距减小,实现宏观晶粒尺寸与微观枝晶间距的细化。
Microstructural Evolutions of 316L Stainless Steel Prepared by Ultrasonic Vibration Assisted Laser Melting Deposition
英文关键词:Ultrasonic vibration  laser melting deposition  316L stainless steel  Grain morphology  Grain size  Solidification mode.
英文摘要:
      Ultrasonic vibrations with ultrasonic powers of 0 W, 600 W, 1000 W and 1400 W were applied during laser melting deposition of 316L stainless steel. The effects of ultrasonic powers on the grain morphologies and sizes, the microstructure formation mechanism and grain growth characteristics of 316L stainless steel were studied. The results show that the application of ultrasonic vibrations can break the directional epitaxial growth of large sized columnar grains, resulting in a refinement of microstructure, and increases of cumulative misorientation and dislocation densitie along the long axis of grains. By promoting the convections in the melt pool, and thus reducing the temperature gradient along the depostion direction, the application of ultrasonic vibrations accelerate the transitions of growth directions for columnar grains. The application of ultrasonic vibrations also help to increase the cooling rate during solidification, resulting in refinements of both columnar grains and the interior columnar dendrites.
作者单位E-mail
柴鹏涛 中国工程物理研究院材料研究所 pengtaochai@163.com 
刘学 中国工程物理研究院材料研究所  
李晋锋 中国工程物理研究院材料研究所  
刘政豪 中国工程物理研究院材料研究所  
杨晓珊 中国工程物理研究院材料研究所  
周昱昭 中国工程物理研究院材料研究所  
王小英 中国工程物理研究院材料研究所  
董鲜峰 中国工程物理研究院材料研究所  
乐国敏 中国工程物理研究院材料研究所 leguomin@126.com 
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