激光辐照下粉末颗粒物态变化特征  

Characteristics of state change of powder particles under laser irradiation

作　　者：杨义成 徐富家 黄瑞生 蒋宝 武鹏博 杜兵 YANG Yicheng;XU Fujia;HUANG Ruisheng;JIANG Bao;WU Pengbo;DU Bing(China Academy of Machinery Science and Technology Group Co.,Ltd.,Beijing 100044,China;Lab.of Materials Welding and Joining,University of Science and Technology Beijing,Beijing 100083,China;Harbin Welding Institute Limited Company,Harbin 150028,China)

机构地区：[1]中国机械科学研究总院集团有限公司,北京100044 [2]北京科技大学,北京100083 [3]哈尔滨焊接研究院有限公司,哈尔滨150028

出　　处：《焊接学报》2022年第11期78-83,I0007,共7页Transactions of The China Welding Institution

基　　金：黑龙江省自然科学基金项目(ZD2019E006);黑龙江省重点研发计划制造类项目(GZ20210186)。

摘　　要：激光与粉末颗粒交互作用后粉末颗粒的物态是目前制约激光同轴送粉加工工艺持续提升的核心要素之一.利用背影增效瞬态影像高速摄影方法清晰获取了激光辐照下粉末颗粒状态随时间变化规律,构建出了激光作用下粉末颗粒飞行过程的动力学模型,对光粉作用区内不同物态特征粒子的演化规律进行了系统研究.结果表明,光粉交互作用区约70%的粉末粒子受到激光辐照,强激光辐照下粒子表面瞬间气化产生高温等离子体形成的反冲作用力是改变粉末粒子运动轨迹和运动速度的原因;激光辐照下粒子运动加速度与“慧尾”长度之间存在映射关系,“慧尾”长度越长,粒子运动加速度越大;粉末粒子的亮度信息在统计学规律上可以定性表征激光辐照下粉末粒子的物态.The state of powder particles after the interaction between laser and powder particles is one of the key factors that restrict the continuous improvement of laser coaxial powder feeding process. Using high speed photography of the shadow enhanced transient image, the change rule of the powder particle state with time under laser irradiation was clearly obtained. The dynamic model of the powder particle flight under laser irradiation was constructed, and the evolution rule of different state characteristic particles in the laser powder interaction zone was systematically studied. The results showed that the more 70% of the powder particles in the laser powder interaction zone were irradiated by laser, and the recoil force generated by the instantaneous vaporization of the particle surface under intense laser irradiation was the reason for changing the movement track and speed of the powder particles. There is a mapping relationship between particle motion acceleration and the length of “comet tail” under laser irradiation. The longer the “comet tail” length, the greater the particle motion acceleration. The brightness information of powder particles can qualitatively characterize the state of powder particles under laser irradiation.

关 键 词：激光同轴送粉 粉末颗粒 物态特性 动力学特征 

分 类 号：TG456.7[金属学及工艺—焊接]