Characteristics and influences of plume during CW laser-CFRP interaction under tangential gas flow

Abstract

The characteristics of plumes during continuous wave laser irradiation of laminated carbon fiber reinforced plastics (CFRP) under tangential air flow or nitrogen gas flow are investigated. The temperature of the plume is measured by the infrared thermal imager. The change in relative mass concentration of the plume is studied by the laser extinction method. The front surface emissivity-corrected temperature maps of CFRP are measured by the infrared thermal imager to estimate the influences of plumes. The highest temperature in the plume is closely related to the absorption of the laser by the plume rather than the combustion effects of the plume. The differences of the plumes, temperature, the material surface temperature and the heat affect zone, under the two different kinds of gas flows, are all due to the effect of the burning of the plume under air flow. As the mass concentration of plumes decreases, these differences gradually disappear or no longer increase. The results of this work can be referenced for the application of the laser processing and the laser damage.