• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2018, Vol. 54 ›› Issue (2): 62-69.doi: 10.3901/JME.2018.02.062

• 特邀专栏:焊接过程测控与数值模拟 • 上一篇    下一篇

焊接熔池凝固过程联生结晶晶体学取向对线性不稳定动力学的影响

郑文健1, 贺艳明1, 杨建国1,2, 董志波2   

  1. 1. 浙江工业大学化工机械设计研究所 杭州 310014;
    2. 哈尔滨工业大学先进焊接与连接国家重点实验室 哈尔滨 150001
  • 收稿日期:2017-08-25 修回日期:2017-12-04 出版日期:2018-01-20 发布日期:2018-01-20
  • 通讯作者: 杨建国(通信作者),男,1975年出生,博士,教授。主要研究方向为焊接力学与可靠性以及焊接计算学。E-mail:yangjg@zjut.edu.cn
  • 作者简介:郑文健,男,1985年出生,博士。主要研究方向为焊接过程数值模拟。E-mail:zwj0322@zjut.edu.cn
  • 基金资助:
    国家重点研发计划(2016YFC0801905)和国家自然科学基金(51475426,51705461)资助项目。

Influence of the Crystal Orientation of Epitaxial Solidification on the Linear Instability Dynamic during the Solidification of Welding Pool

ZHENG Wenjian1, HE Yanming1, YANG Jianguo1,2, DONG Zhibo2   

  1. 1. Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou 310014;
    2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001
  • Received:2017-08-25 Revised:2017-12-04 Online:2018-01-20 Published:2018-01-20

摘要: 为了研究焊接熔池凝固过程中联生结晶的晶体学取向对线性不稳定动力学的影响规律,采用定量相场模型,耦合熔合线附近枝晶生长的瞬态条件,对不同晶体学取向的联生结晶生长过程进行数值模拟,同时采用考虑界面能各向异性的线性不稳定动力学解析模型对该系列联生结晶过程的界面演化进行预测。线性生长失稳波长的相场模拟结果和解析计算结果与试验结果吻合良好。不同晶体学取向的联生结晶的生长结果表明,晶体学取向偏角越大,界面越稳定,界面失稳临界时间越长。由于焊接熔池瞬态凝固条件的瞬变性,以及线性生长阶段界面波长选择放大机制的随机性,使晶体学取向偏角越大界面失稳波长越大的规律无法显现。因此焊接熔池中熔合线附近联生结晶的界面失稳胞晶间距与初始晶体学取向相关性不明显。

关键词: 焊接熔池凝固, 晶体学取向, 联生结晶, 线性不稳定, 相场

Abstract: To study the influence of the crystal orientation of epitaxial solidification on the linear instability dynamic, coupled equations are conducted to present the transient conditions of crystal growth near the fusion line of the welding pool. A quantitative phase field model is used to simulate the epitaxial solidification with different crystal orientations. Moreover, a linear instability dynamic analytical model is presented to describe the variation of the onset of the initial planar instability with surface tension anisotropy. The initial average wavelengths obtained by the phase field model and the analytical model are in good agreement with that in experiment result. The epitaxial solidification results show that the greater the angle between the crystal orientation and the temperature gradient, the better the stability of the interface, and the larger the critical time of onset of initial planar instability. Due to the transient of the growth conditions in welding pool and the randomness of the amplification mechanism, it could not show up the law that the greater the crystal orientation angle, the larger the initial average wavelength. Thus, the initial average wavelength of planar instability is seemly independent of the crystal orientation of epitaxial solidification.

Key words: crystal orientation, epitaxial solidification, linear instability, phase field, solidification of welding pool

中图分类号: