中文摘要：

射流形态是熔射过程中最直观的射流信息，它是熔射各工艺参数稳定与否的直接反映。本文提出基于CCD对氩氮等离子熔射射流进行图像采集，利用数字图像处理方法提取射流形态，以射流狭长度来描述射流形态特征的识别方法。实验研究结果表明：射流狭长度特征可以很好地反映不同工艺条件下射流的形态特点；通过实验分析主要工艺参数对该特征的影响规律，得到输入电压对该特征有主要影响的结果；结合相应工艺条件下粒子飞行行为检测实验结果，对该射流诊断系统进行验证，表明该系统可实际应用于RSTP的工艺分析中。

英文摘要：

The morphology of plasma jets directly demonstrates the information on them in spray processes, thus revealing the stability of all spray parameters. The paper proposes a pattern recognition method for describing the morphological features of plasma jets in terms of aspect ratio by collecting the images of argon and nitrogen plasma jets, extracting their shapes using the digital image processing method. The research results indicate that the aspect ratio feature of plasma jets can effectively reflect their morphological features in various process conditions. The analysis of the influence of main process parameters on the features produces the outcome that input voltage is the primary influence factor. The measurement experiment on the in-flight particle behavior was carried out to verify the spray diagnosis system of plasma jets, and the verification results show that the system can be put into use for the process analysis in the rapid plasma spray process.