High-speed heat accumulation temperature measurement in high-throughput laser surface texturing for advanced coating substrate preparation

Laser material micro-processing with high repetition frequencies of laser pulses is able to initiate heat accumulation effects that can decrease processing rate and quality. In order to gain deeper insights into these effects, a temperature measurement system with nanosecond time resolution was developed using infrared detector and a set of parabolic mirrors. For measurement in more industrially relevant processes on larger areas, alternative configurations were developed: measurement through the scan head and multifocus ellipsoidal mirror. This work is initially focused on comparison of advantages and limitations of the developed measurement configurations by signal to noise ratio, field of view and measurable temperature range. The measurement systems were then used for the analysis of polygon scanner based high-speed laser surface texturing of steel and ceramics substrates as a preparation method for thermal spraying of coatings. GHz burst femtosecond laser ablation was analyzed and long-time process monitoring using FPGA hardware analysis was developed and performed for the laser texturing process.

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