基于三探针检测的TC4钛合金激光深熔焊等离子体动态行为研究

Study on dynamic behavior of plasma in deep penetration laser welding of TC4 titanium alloy based on triple-probe detection

在激光深熔焊中,激光诱导等离子体的产生具有很强的随机性和时变性.利用新型无源三探针电信号采集装置,采集高时间分辨率的等离子体电信号,获得大样本的等离子体温度等热力学信息,采用无监督学习方法中的K-均值聚类对复杂的等离子体动态行为聚类分析.结果表明,在文中试验条件下,等离子体的喷发频率主要集中在1240-2200 Hz范围,等离子体喷发的温度变化率主要分布在5000-30000 K/ms的范围内;等离子体的摆动频率主要在1050-1410 Hz范围,等离子体摆动的温度变化率主要分布在200-2000 K/ms的范围内,喷发和摆动的温度变化率差异明显.

In deep penetration laser welding,the generation of the laser-induced plasma exhibits significant randomness and temporal variability.A novel passive triple-probe electrical signal acquisition device was utilized to collect the plasma electrical signals with high temporal resolution,thereby obtaining the large sample of thermodynamic information,including plasma temperature.K-means clustering,an unsupervised learning method,was used to conduct the clustering analysis of the complex dynamic behaviors of the plasma.The results indicated that under the experimental conditions of present work,the frequency of the plasma eruption mainly fell within the range of 1240-2200 Hz,and the temperature change rate was primarily distributed between 5000-30000 K/ms.Additionally,the sway frequency of the plasma was mainly observed in the range of 1050-1410 Hz,and the temperature change rate concentrated between 200-2000 K/ms.Consequently,there was a significant difference in the temperature change rates between plasma eruption and sway.