同轴送粉激光熔覆中激光透过率研究  

Study on Laser Transmittance in Coaxial Laser Cladding

作　　者：申卫国[1] 岑虎 雷剑波[1] 刘立峰[1] 王云山[1] 

机构地区：[1]天津工业大学机械工程学院,天津300387

出　　处：《机械工程学报》2014年第8期59-65,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金(60908017);天津市应用基础及前沿技术研究计划(12JCQNJC02800);天津市高等学校科技发展基金计划(20120631)资助项目

摘　　要：研究同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，建立同轴送粉中粉末流浓度场理论模型，对粉嘴结构参数进行优化；基于Beer-Lambert定律，建立同轴送粉激光熔覆中激光透过粉末流的透过率数理模型，重点分析粉末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15宽度为0．4mm且粉腔外壁倾角选为180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0～50mg／s时，理论计算结果与试验结果基本一致。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 stream 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 of 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 cart be found that laser powder attenuation by powder stream tends to increase with increasing powder flow rate when the structure parameters of the nozzle 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.

关 键 词：激光技术 激光熔覆 透过率 粉末流 Beer-Lambert定律 

分 类 号：TN249[电子电信—物理电子学]