激光增材制造技术已经在多个领域得到应用, 但是由于缺乏对制造过程进行相应的监测和诊断, 阻碍了该技术在对产品质量有严格要求的高精尖领域的发展应用。采用分析激光诱导等离子体光谱的方法对激光增材制造过程中FeCr混合粉末中的Cr元素进行在线监测。首先通过实验采集光谱数据; 其次找到Cr浓度与光谱特性之间的关系; 最后根据相关的光谱特性建立Cr浓度监测模型。本文使用的化学计量法为支持向量回归, 实验结果表明该模型能较为准确地预测激光增材制造过程中的Cr浓度。当Cr浓度为11.9%时, 整个过程的绝对标定误差为0.67%, 相对标定误差为5.04%, 相对标准误差为4.23%。将SVR模型应用到在线监测中, 发现预测值以很小的幅度在实际的Cr浓度值附近上下波动。

Laser additive manufacturing technology has been applied in many fields, but due to the lack of corresponding monitoring and diagnosis of the manufacturing process, it hinders the development and application of this technology in the highly sophisticated field where the quality of products is strictly required. In this paper, the laser induced plasma method is used to monitor the composition of Cr in the laser additive manufacturing process. Firstly, the spectral data is collected by experiment. Secondly, the spectral characteristics affecting the Cr concentration are found. Finally, the Cr concentration monitoring model is established according to the relevant spectral characteristics. The model used in this paper is the support vector machine model. The experimental results show that the model can accurately predict the Cr concentration in the laser additive manufacturing process. When the Cr concentration is 11.9%, the absolute error of calibration of the whole process is 0.67%, the relative error of calibration is 5.04%, and the relative standard error is 4.23%. When the model was applied to component monitoring, it was found that the predicted value fluctuated around the actual Cr concentration value with a small amplitude.