• CN:11-2187/TH
  • ISSN:0577-6686

›› 2009, Vol. 45 ›› Issue (10): 241-247.

• 论文 • 上一篇    下一篇

基板预热对激光金属沉积成形过程热应力的影响

龙日升;刘伟军;邢飞;王华兵;卞宏友   

  1. 中国科学院沈阳自动化研究所;中国科学院研究生院
  • 发布日期:2009-10-15

Effects of Substrate Preheating on Thermal Stress during Laser Metal Deposition Shaping

LONG Risheng;LIU Weijun;XING Fei;WANG Huabing;BIAN Hongyou   

  1. Shenyang Institute of Automation, Chinese Academy of Sciences Graduate School, Chinese Academy of Sciences
  • Published:2009-10-15

摘要: 为降低沉积过程的热应力,抑制成形过程中裂缝的产生,研究基板预热对激光金属沉积成形(Laser metal deposition shaping, LMDS)过程热应力的影响具有非常重要的意义。根据有限元分析中的“单元生死”思想,利用APDL (ANSYS parametric design language)编程建立多道多层激光金属沉积成形过程的数值模拟模型,深入探讨基板未预热和预热到400 ℃时对成形过程热应力的影响。计算结果表明,基板预热到400 ℃可以显著降低成形过程中试样的热应力变化波动性,试样的Von Mises热应力最大值可降低10%左右,其中x方向热应力最大值可降低8.5%左右,z方向热应力最大值可降低8.1%左右。在与模拟过程相同的条件下,利用自行研制的激光金属沉积成形设备进行了成形试验,成形试验的结果与模拟结果基本吻合。

关键词: 基板预热, 激光金属沉积成形, 热应力, 数值模拟

Abstract: In order to decrease the thermal stress and suppress the generation of cracks during LMDS process, it is of great importance to understand the effects of substrate preheating on thermal stress. According to the “element birth and death” technique of finite element analysis (FEA), a three-dimensional multi-track and multi-layer numerical simulation model for LMDS is developed with APDL. Through the model, the effects of preheating on thermal stress are deeply researched by setting the temperature of substrate at room temperature or 400 ℃. The results show that preheating can remarkably decrease the thermal stress fluctuation of sample, and at the same time preheating can decrease the Von Mises thermal stress of sample by 10 percent, and decrease the x-direction thermal stress by 8.5 percent and decrease the z-directional thermal stresses by 8.1 percent. Using the same process parameters, the features of samples fabricated by self-developed LMDS system show good agreement with the simulation results.

Key words: Laser metal deposition shaping, Numerical simulation, Substrate preheating, Thermal stress

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