Investigation of the micro-milling process of steel with THz bursts of ultrashort laser pulses. (July 2023)

• Record Type: Journal Article
• Authors: Gaudiuso, Caterina; Stampone, Benedetta; Trotta, Gianluca; Volpe, Annalisa; Ancona, Antonio
• Is Part Of: Optics & laser technology. Volume 162(2023)
• Publication Date: 2023-07
• Subjects: Burst mode processing -- Surface finishing -- Ultrafast lasers -- Laser micro-milling -- Design of experiment (DoE); Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2023.109301
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: The systematic investigation of laser micro-milling processing with bursts in the THz regime is carried out to evaluate their influence on the ablation depth and the surface roughness. Statistical methods based on a Design of Experiments approach are used to manage the numerous process parameters which are involved in laser micro-milling and prediction models for the ablated depth and the surface roughness are defined. High quality surface finishing (low surface roughness) is ensured by using burst mode irradiation. Abstract: Burst mode (BM) processing with femtosecond laser pulses is emerging as a versatile tool for manufacturing micro-components on different materials, thanks to its ability to reduce the thermal load, which ensures highly precise and accurate miniaturization. However, a systematic investigation of the influence of the experimental parameters introduced by such irradiation mode, i.e., the number of pulses within the burst, their polarization and the intra-burst frequency, on the ablation process has not been reported, yet. In this work, we exploited a statistical approach based on the Design of Experiment (DoE) to study the micro-milling process of steel with bursts. Two prediction models were defined, describing the relationship between the working parameters, i.e., average power, number of overscans, laser repetition rate, scan speed and number of pulses within the bursts, and the response variables, i.e., ablated depth and surface roughness, revealing burst mode as a very promising solution to improve the surface finishing of ultrashort laser pulses micromilled components.