同轴送粉激光熔覆中激光透过率研究.pdf

兔w. xuetie,com
第50卷第8期
机槭工程学报
2014年4月
JOURNAL OF MECHANICAL ENGINEERING
2014
DOI:10.3901/JME.2014,08.059
同轴送粉激光熔覆中激光透过率研究
申卫国岑虎雷剑波刘立峰王云山
(天津工业大学机械工程学院天津300387
摘要:研究冋轴送粉激光熔覆中激光透过粉末流机理,对激光制造工艺参数的优化及制造过程检测控制具有直接指导意义。
重点研究粉末流沿粉嘴中心轴线方向的浓度分布,建立问轴送粉中粉末流浓度场理论模型,对粉嘴结构參数进行优化;基于
Beer-lambert定律,建立同轴送粉激光焠覆中激光透过粉末流的透过率数理模型,重点分析粉未流量对激光透过率的影响
开发一种测试同轴送粉激光熔覆中激光透过功率的系统。结果表明,出粉口宽度为0.4mm且粉腔外壁倾角选为18时,粉
末流的几何形貌及汇聚性较好;在粉嘴结构参数一定时,粉末流量越大,对激光的衰减越强,激光透过率越低:激光功率选
为200W、300W、400W,粉末流量取0~50mgs时,理论计算结果与试验结果基本一致
关键词:激光技术;激光熔覆;透过率;粉末流; Beer-lambert定律
中图分类号:TN249
Study on Laser Transmittance in Coaxial Laser Cladding
SHEN Weiguo CEN Hu LEI Jianbo LIU Lifeng WANG Yunshan
(School of Mechanical Engineering, Tianjin Polytechnic University, Tianjin 300387)
Abstract: The research of mechanism of laser passing through powder stream in coaxial laser cladding is of great significance for
optimization of laser cladding process parameters and detective controls in the manufacturing process. The paper is focused in
theoretical model of concentration field for powder ream from coaxial nozzle. Based on the model, the distributions of
concentration of powder stream along central axis are simulated, geometric parameters of the nozzle are optimized. Theoretical
model of laser passing through powder stream in coaxial laser cladding has been presented from Beer-lambert law. The influence o
powder flow rate on the laser transmittance has been discussed in view of the model. The system used for testing the power of the
laser that has passed through powder stream in coaxial laser cladding is developed. It is shown that the geometric shape is fine while
the width of the powder outlet is 0.4 mm and the angle of the outer powder cavity is 18. It can be found that laser powder
attenuation by powder stream tends to increase with increasing powder flow rate when the structure parameters of the nozze are
fixed. The results of the experiment shows that the deviation between theoretical values is consistent with experimental values while
the laser power is 200 W. 300 W 400 W and powder flow is choose in the range of from 0 to 50 mg/s
Key words: laser technology; laser cladding; transmittance; powder stream; Beer-lambert law
熟,当前国内外学者在这方面开展了大量的研
究。汪洋等?在激光制造过程的检测与控制方面开
展了研究,开发出能对工件表面实时检测的三维激
目前,3D打印技术作为一种通过逐层叠加制造光扫描系统; FERRAR等”研究了激光选区熔化制
来生成三维实体的新兴技术,在国内外受到广泛关造复杂结构零件;刘佳等?在激光制造的工艺优
注,已成为快速成形领城的前言和热点课题。作化与改进方面进行了研究;YASA等在材料选
为3D打印技术行业中的典型技术之一,激光直接择及零件微观组织与性能方面开展深入的研究。
成形制造近年来得到飞速发展并在装备方面渐趋成
同轴送粉激光熔覆作为激光直接成形制造的
重要组成部分,能将粉末流均匀地成环状分散后再
国家自然科学基金(090天)津市应用基础及前沿技术研究计划汇聚送入聚焦后的激光束,在 CAD/CAM驱动下送
12QNUC2800和天準市高等学校科技发展基金计?2012061)资助项粉工作头像金属笔一样,逐层熔覆堆积,实现三维
目。20130515收到初稿,20131231收到修改稿