航空学报 > 2022, Vol. 43 Issue (4): 525603-525603   doi: 10.7527/S1000-6893.2021.25603

钛合金激光砂带加工的离焦控制与表面形貌

肖贵坚, 刘帅, 贺毅, 刘岗, 朱升旺, 宋沙雨   

  1. 重庆大学 机械与运载工程学院, 重庆 400044
  • 收稿日期:2021-03-30 修回日期:2021-05-11 发布日期:2021-07-20
  • 通讯作者: 肖贵坚 E-mail:xiaoguijian@cqu.edu.cn
  • 基金资助:
    国家自然科学基金(52175377);国家科技重大专项(2017-VII-0002-0095)

Defocus control and surface topography of titanium alloy laser belt processing

XIAO Guijian, LIU Shuai, HE Yi, LIU Gang, ZHU Shengwang, SONG Shayu   

  1. College of Mechanical and Transportation Engineering, Chongqing University, Chongqing 400044, China
  • Received:2021-03-30 Revised:2021-05-11 Published:2021-07-20
  • Supported by:
    National Natural Science Foundation of China (52175377);National Science and Technology Major Project (2017-VII-0002-0095)

摘要: 钛合金由于优越的热机械特性(耐高温和耐腐蚀)而被广泛应用于航空航天、核电领域,但独特的低导热系数、高强度和加工硬化性能导致其加工困难,表面完整性难以保持。激光辅助加工方法可以有效地提高难切削材料的切削性能,提高其表面完整性。提出一种激光加工与砂带磨削融合的特种加工方法(激光砂带加工方法),建立了激光砂带加工的焦点控制运动模型,通过对焦点的控制实现利用激光加热特性和砂带磨削柔性特性快速去除材料,在自行搭建的激光砂带加工实验平台进行了加工实验,对不同离焦量下激光砂带加工的钛合金样品的表面三维形貌、微观结构进行了分析和比较。结果表明,激光砂带加工过程中离焦量的大小极大程度影响了激光的能量分布,导致激光砂带加工机理发生变化,离焦量的减少导致表面算术平均偏差Sa先从8.07 μm减少到7.40 μm然后增加到22.1 μm,材料的气化和熔化去除现象更加明显。最后证明了激光砂带加工方法可以改善钛合金的加工性能,提升表面的耐磨损性能,具有广阔的应用前景。

关键词: 钛合金材料, 激光砂带, 离焦控制, 表面形貌, 热机械特性

Abstract: Although titanium alloy is widely used in aerospace and nuclear power fields due to its superior thermomechanical properties (high temperature resistance and corrosion resistance), its unique low thermal conductivity, high strength and work hardening properties make it difficult to process and maintain surface integrity. Laser-assisted processing methods can effectively improve the cutting performance of difficult-to-cut materials and improve their surface integrity. Therefore, this paper proposes a special processing method (laser belt processing method) that combines laser processing and belt grinding, and establishes a focus control movement model for laser belt processing by using laser heating characteristics and sanding to control the focus. With the flexible characteristics of grinding, the material can be quickly removed. The processing experiment is carried out on the self-built laser abrasive belt processing experimental platform. The surface three-dimensional morphology and microstructure of the titanium alloy samples processed by the laser abrasive belt under different defocusing amounts are analyzed and compared. The results show that the amount of defocus during the laser abrasive belt processing greatly affects energy distribution of the laser, leading to changes in the laser abrasive belt processing mechanism; the reduction in the amount of defocus causes the surface roughness Sa to first decrease from 8.07 μm to 7.40 μm, then increases to 22.1 μm; the phenomenon of material gasification and melting removal becomes more obvious. Finally, it is proved that the laser abrasive belt processing method can improve the processing performance of titanium alloy, and can improve the wear resistance of the surface, which has broad application prospects.

Key words: titanium alloy, laser belt grinding, defocus control, surface topography, thermomechanical properties

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