• CN:11-2187/TH
  • ISSN:0577-6686

›› 2014, Vol. 50 ›› Issue (21): 152-158.doi: 10.3901/JME.2014.21.152

• 论文 • 上一篇    下一篇

电子束选区熔化成形316L不锈钢的工艺研究

郭超;林峰;葛文君   

  1. 清华大学机械工程系;清华大学先进成形制造教育部重点实验室;清华大学生物制造与快速成形技术北京市重点实验室
  • 出版日期:2014-11-05 发布日期:2014-11-05

Study on the Fabrication Process of 316L Stainless Steel via Electron Beam Selective Melting

GUO Chao;LIN Feng;GE Wenjun   

  • Online:2014-11-05 Published:2014-11-05

摘要: 电子束选区熔化是一种利用电子束逐层熔化金属粉末制造三维实体零件的增材制造技术,在航空航天、医学植入体等领域有很好的应用前景。利用316L不锈钢粉末为材料,研究粉末熔化阶段电子束功率恒定、单遍扫描对成形件上表面粗糙度的影响。发现电子束功率P与扫描速度v的比值是影响上表面形貌的关键因素,随着P/v值的增加,上表面形貌由网结状变化为沟壑状,同时粉末材料的飞溅增加。研究上表面形貌随成形高度增加而演变的过程,发现形貌随高度增加不断恶化,并解释了形貌恶化的原因。提出电子束功率递增、多遍扫描的方法,先用低功率电子束使粉末材料熔化聚球但不飞溅,再用大功率电子束使材料重新熔化并充分流动、浸润。这种方法改善了成形件上表面的形貌,表面粗糙度Ra小于8 μm,获得的组织均匀细密,致密度高达99.96%。相对于单遍扫描,多遍扫描不会造成主要元素的额外烧损。

关键词: 表面形貌, 电子束, 扫描方法, 选区熔化, 增材制造, 仿真, 钢轨打磨, 接触, 砂带

Abstract: Electron beam selective melting (EBSM) is an additive manufacturing technology that utilizes an electron beam to build three-dimensional object layer by layer from metal powder, and can be applied in manufacturing aerospace components and medical implants. Effect of the single-pass scanning with constant power on the top surface topography is studied by using the 316L stainless steel powder material. It’s found that the ratio of the electron beam power P to the scanning velocity v is the key factor affecting the top surface topography. With the increase of P/v, the top surface topography changes to a gully type from a balling-net type, and the spatters increase. The evolution of the top surface topography with the increase of the fabricated height is also studied. And it’s found that the topography worsens with the increase of the fabricated height. The reasons for the topography worsening are explained in detail. A multi-pass scanning process with progressively increasing power is developed, and it largely improves the top surface topography of the fabricated parts. The roughness Ra of the top surface is lower than 8 μm. Uniform and fine microstructures can be obtained, and the relative density of the fabricated sample reaches up to 99.96%. Compared to the single-pass process, the multi-pass process does not cause additional melting loss of the elements.

Key words: additive manufacturing, electron beam, scanning method, selective melting, surface topography, Abrasive belt, Contact, Rail grinding, Simulation

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