Remote Laser Cutting of CFRP: Improvements in the Cut Surface

Stock, Johannes; Zaeh, Michael F.; Conrad, Markus

doi:10.1016/j.phpro.2012.10.026

Cited by 69 publications

(16 citation statements)

References 5 publications

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“…In short laser pulses, the laser radiated energy absorbed and stored by the free electrons for about 1 ps; then, the energy is converted into heat and transferred to the materials lattice leading to the ablation of target material [24]. During short picosecond laser processing (wavelength 1064 nm) of CFRP composite, the laser energy is mainly absorbed by carbon fibres due to the higher absorbent of carbon fibre to the nearinfrared wavelength compared to the epoxy which is approximately transparent [25]. Despite the low photon energy of the laser used, the high peak intensity results in direct ablation of the materials, whereas some of the heat is conducted along the fibres due to the high thermal conductivity of the fibre (50 W/m k) compared to the epoxy resin (0.1 W/m k) and leads to evaporation of surrounding matrix.…”

Section: Discussionmentioning

confidence: 99%

High-power picosecond laser drilling/machining of carbon fibre-reinforced polymer (CFRP) composites

Salama

Mativenga

et al. 2016

Appl. Phys. A

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The large differences in physical and thermal properties of the carbon fibre-reinforced polymer (CFRP) composite constituents make laser machining of this material challenging. An extended heat-affected zone (HAZ) often occurs. The availability of ultrashort laser pulse sources such as picosecond lasers makes it possible to improve the laser machining quality of these materials. This paper reports an investigation on the drilling and machining of CFRP composites using a state-of-the-art 400 W picosecond laser system. Small HAZs (\25 lm) were obtained on the entry side of 6-mm-diameter hole drilled on sample of 6 mm thickness, whereas no HAZ was seen below the top surface on the cut surfaces. Multiple ring material removal strategy was used. Furthermore, the effect of laser processing parameters such as laser power, scanning speed and repetition rate on HAZ sizes and ablation depth was investigated.

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Section: Discussionmentioning

confidence: 99%

High-power picosecond laser drilling/machining of carbon fibre-reinforced polymer (CFRP) composites

Salama

Mativenga

et al. 2016

Appl. Phys. A

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“…The HAZ plotted is the cross-sectional HAZ (1064 nm) and Yb-fibre laser (1070 nm) where the laser is mainly absorbed by the carbon fibre and is normally transparent to polymer. These near-IR lasers heat the carbon fibre, and the heat is conducted from the carbon fibre to the polymer; thus, it is less affective and generates larger heat-affected zones [7,38]. Furthermore, the high peak power of TEA CO 2 laser (250 kW) released on a short time results in rapid ablation of the CFRP composite leaving little time for the heat to propagate to the surrounding materials, and the cooling time between the pulses further improves the machining equality.…”

Section: Discussionmentioning

confidence: 99%

TEA CO2 laser machining of CFRP composite

Salama

Mativenga

et al. 2016

Appl. Phys. A

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Carbon fibre-reinforced polymer (CFRP) composites have found wide applications in the aerospace, marine, sports and automotive industries owing to their lightweight and acceptable mechanical properties compared to the commonly used metallic materials. Machining of CFRP composites using lasers can be challenging due to inhomogeneity in the material properties and structures, which can lead to thermal damages during laser processing. In the previous studies, Nd:YAG, diode-pumped solidstate, CO 2 (continuous wave), disc and fibre lasers were used in cutting CFRP composites and the control of damages such as the size of heat-affected zones (HAZs) remains a challenge. In this paper, a short-pulsed (8 ls) transversely excited atmospheric pressure CO 2 laser was used, for the first time, to machine CFRP composites. The laser has high peak powers (up to 250 kW) and excellent absorption by both the carbon fibre and the epoxy binder. Design of experiment and statistical modelling, based on response surface methodology, was used to understand the interactions between the process parameters such as laser fluence, repetition rate and cutting speed and their effects on the cut quality characteristics including size of HAZ, machining depth and material removal rate (MRR). Based on this study, process parameter optimization was carried out to minimize the HAZ and maximize the MRR. A discussion is given on the potential applications and comparisons to other lasers in machining CFRP.

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“…Экспери-мент повторяли до тех пор, пока максимальная скорость подачи для заданного числа проходов не была определена. Пренебрегая потерями энергии, количество энергии испарения материала считали неизменным, независимо от числа проходов [6]. Таким образом, суммарная энергия…”

Section: рисunclassified

“…Обычно при обработке лазерных материалов относительное перемещение реализуется либо с помощью движе-ния заготовки, либо путем перемещения луча по линейной оси, а также с ис-пользованием сканаторных систем [6].…”

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