东北大学学报:自然科学版 ›› 2014, Vol. 35 ›› Issue (12): 1710-1714.DOI: 10.12068/j.issn.1005-3026.2014.12.009

• 材料与冶金 • 上一篇    下一篇

激光熔覆多层Nb-Si-Ti显微组织

梁京, 陈岁元, 刘常升, 陈炜   

  1. (东北大学 材料各向异性与织构工程教育部重点实验室, 辽宁 沈阳110819)
  • 收稿日期:2013-11-28 修回日期:2013-11-28 出版日期:2014-12-15 发布日期:2014-09-12
  • 通讯作者: 梁京
  • 作者简介:梁京(1972-),女,辽宁沈阳人,东北大学副教授; 陈岁元(1964-),男,甘肃天水人,东北大学教授,博士生导师; 刘常升(1963-),男,内蒙古奈曼旗人,东北大学教授,博士生导师.
  • 基金资助:
    国家自然科学基金青年科学基金项目(50201030); 中央高校基本科研业务费专项资金资助项目(N100702001); 中央高校基本科研业务费青年教师科研创新基金资助项目(N110410007); 辽宁省自然科学基金资助项目(2013020099).

Microstructure of Laser Cladding Multi-layer Nb-Si-Ti

LIANG Jing, CHEN Sui-yuan, LIU Chang-sheng, CHEN Wei   

  1. Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education, Northeastern University, Shenyang 110819, China.
  • Received:2013-11-28 Revised:2013-11-28 Online:2014-12-15 Published:2014-09-12
  • Contact: LIANG Jing
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摘要: 采用基于多层激光熔覆的激光快速成形方法,通过优化激光扫描过程参数,调整不同成分元素粉末来进行铌硅基自生复合材料的显微组织和成分设计研究.采用Nd:YAG激光器扫描预置在Ti-6Al-4V基材上成分为Nb-18Si-24Ti(原子分数)混合粉末,获得所需激光熔覆层.优化出工艺参数为激光脉冲电流225A,扫描速度3.0mm/s,激光脉冲频率15Hz,激光脉冲宽度3.0ms,离焦量15mm,并在优化参数下制备出了4层多道样品.分别采用OM,SEM及XRD对预置法制备出的多层沉积层的显微组织及相结构进行分析,结果显示在多层沉积层中获得了铌硅固溶体Nbss,硅化物Nb5Si3和Nb3Si等相,随着沉积层数的增加,Nb,Si含量逐渐增加,显微组织由接近于基体的细小枝晶转变为在最顶层的深色岛状Nb5Si3,灰色条状或岛状Nb3Si及白色Nbss.

关键词: 激光多层熔覆, Nb-Si-Ti, 铌硅基自生复合材料, 显微组织, 成分设计

Abstract: The microstructure and composition design of the niobium silicide based composites which prepared by direct laser fabrication based on multi-layer laser cladding through optimizing laser scanning parameters and adjusting the composition ratio of the mixed element powders were investigated. Element powders mixture Nb-18Si-24Ti(at.%)was prepasted on a substrate of Ti-6Al-4V and scanned by a 500W pulsed Nd:YAG laser. Four-layer specimens were fabricated under the optimized laser processing parameters with electric current of 225A, laser scanning speed of 3.0mm/s, pulsed frequency of 15Hz, defocus length of 15mm. Microstructures and phases of the prepared specimens were analyzed by OM, SEM and XRD, respectively. Results showed that Nb5Si3, Nb3Si and Nbss are formed in the multilayer laser cladding coatings. With the increase of the number of layers, the Nb and Si contents increase gradually, tiny dendrites are found in the layer near the substrate while the top layer contain island-shape grey phases distributed in the continuous white phases.

Key words: multi-layer laser cladding, Nb-Si-Ti, niobium silicide based in-situ composites, microstructure; composition design

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