Passive electric detection device and method for laser plasma

Abstract

The invention discloses a passive electric detection device and method for laser plasma. The device consists of two parallel sections and an arc section, wherein the two parallel sections are parallel to each other and connected through the arc section; the whole device is in an M shape; a cross section of the electric detection device is rectangular; a flow channel is formed inside the electric detection device and used for flowing and circulation of water; the two parallel sections are connected with water pipes respectively; and a lead is arranged on the electric detection device and used for performing electric signal detection on the laser plasma. During testing, a laser acting point is located in a concave part of the device, and a ceramic pad is arranged between a to-be-welded object and the M-shaped electric detection device to keep insulation and avoid short circuit; the electric detection lead is connected with a data acquisition card, the data acquisition card is connected with a computer, and data acquisition preparation work is ready; and then water is supplied for cooling. According to the electric detection method for the laser plasma, the stability and the reliability of a real-time electric detection process for the temperature of the laser plasma during laser welding are improved, and the method is easy to implement.

Description

technical field [0001] The invention belongs to the material processing technology, and more specifically relates to a method and a device for detecting the properties of laser plasma in a laser welding process. Background technique [0002] Laser welding is an important welding method. In the process of laser welding, photo-induced plasma, also known as laser plasma, will be generated, which has an important impact on the welding process. Metal evaporation will occur inside the laser plasma, and the radiation, scattering and absorption of energy will shield the laser and directly affect the welding process. The application purpose of the present invention is to detect the laser plasma, detect the temperature of the laser plasma in real time, and help to implement the quality monitoring of the laser welding process. In terms of plasma detection using electrical probes, Langmuir probe is the most widely used, which is an active probe suitable for the detection of steady-stat...

AI Technical Summary

Problems solved by technology

[0004] 2) The laser plasma cloud (laser plasma outside the molten pool) has certain volatility, and the rod-shaped probe has a small diameter and a limited detection range. The swaying fluctuation of the laser plasma cloud may make the probe detect at certain moments or conditions less than plasma

In order to make the detection more reliable, the probe should be as close as possible to the center of the plasma cloud (the passage of the laser beam), and to prevent it from being burned by the laser, its positioning and adjustment are very difficult

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