Fibre laser piercing of mild steel – The effects of power intensity, gas type and pressure

Hashemzadeh, Majid; Powell, John; Voisey, K.T.

doi:10.1016/j.optlaseng.2013.10.001

Cited by 15 publications

(3 citation statements)

References 15 publications

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“…Piercing and laser cutting are two independent processes in which material evacuation have different mechanisms [1,2]. In the piercing, the laser beam is stationary with respect to the workpiece and the melt material is ejected upwards.…”

Section: Introductionmentioning

confidence: 99%

“…The authors developed a new piercing technique known as PRPM (power ramped pulsed mode) obtaining smaller piercing holes with greater circularity and less ejected material than in normal pulse mode. In mild steel, researchers [2,11] observed that increasing the power of the peak or the duty cycle, increased the size of the hole and the irregularity of its shape and ejected material, also obtaining wider piercings with oxygen assist gas than with nitrogen. Pocorni et al [12] investigated the piercing process in the laser cutting of stainless steel, demonstrating that appropriate laser power modulation settings could considerably reduce both the piercing time and the required energy to generate the piercing hole, also affecting its size.…”

Section: Introductionmentioning

confidence: 99%

“…The monitored signal intensity is evaluated and related to changes in piercing process parameters for mild steel, stainless steel, and aluminum thick sheets. Actually, it is possible to find commercial devices to detect the end of the piercing [15][16][17] or to optimize it by adjusting only laser power [18][19][20], or scientific studies on piercing that are focused on investigating the relationship between process parameters and piercing appearance [2,11,12]. This work will contribute to creating know-how on the influence of process parameters in laser piercing, to improving their duration and the development of new piercing strategies thanks to the possibility of efficiently modifying the piercing parameters based on parameter dependencies.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Process Parameters in Laser Piercing

Garcia¹,

Ramos²,

Lamíkiz

et al. 2019

Applied Sciences

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This work addresses the analysis of the influence of process parameters in laser piercing for mild steel, stainless steel, and aluminum thick sheets, carried out by the monitorization of the signal with a photodiode installed coaxially in the cutting head. The sensor captures the infrared or visible signal emitted during the piercing. The relationship between the intensity of the signal and the parameter values was analyzed, distinguishing between soft and fast piercings. The results permit the optimization of the piercing strategy with a reduction of 25% in time and the possibility of establishing a threshold to control the piercing process. This study reveals the importance of knowing parameter dependencies with the process results and highlights the potential of monitorization systems in laser cutting to improve the piercing duration and avoid wasting time during production.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Process Parameters in Laser Piercing

Garcia¹,

Ramos²,

Lamíkiz

et al. 2019

Applied Sciences

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Laser Cutting, Drilling, and Piercing

Walia,

Varshney,

Singh

2024

Laser‐Assisted Machining

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Laser Cutting Head for High‐Brightness Lasers

Wolff¹,

Karam²,

Groß³

2016

Laser Technik Journal

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II-VI HIGHYAG, a subsidiary of II-VI Inc., is one of the world's leading suppliers in the laser material processing industry. Its innovative laser processing heads and beam delivery systems enable the efficient use of the laser beam for the most dem anding advanced manufacturing applications such as laser cutting, laser welding and laser brazing. www.highyag.com CompanyThe present market of metal laser cutting machines is mainly dominated by laser sources that emit radiation in the wavelength range around one micron. The majority of these lasers generate radiation through pumping of ytterbium doped fiber or ytterbium doped disks, or directly from gallium arsenide (GaAs) semiconductor diodes. The latter direct diode approach has been increasing its market share due to a significant increase of beam quality. A few years ago, high-power direct diode lasers were used for applications where low brightness (BPP between 20 -30 mm mrad @ 4 kW) was sufficient, such as laser brazing and hardening. With the latest improvements in beam quality, reaching 4 mm mrad and below, direct diode lasers are now suitable for laser cutting applications, which are dominated currently by other laser types. This article investigates cutting quality and speed using the II-VI Highyag laser cutting head BIMO-FSC in combination with a direct diode laser. In addition, the machine controlled and independent adjustment of focus position and diameter of the BIMO-FSC have been analyzed in regards to optimization of the piercing process.Typically, laser processing head manu facturers design optical layouts for a rather small wavelength bandwidth in order to avoid the need for broadband coatings that are typically more expen sive and thicker. Increasing thickness of coatings will result in a higher absorp tion and hence higher tendency of focus shift. This is one of the reasons why IIVI Highyag tailored its laser cut ting head BIMOFSC to be used with highbrightness diode lasers. The one used for the investigation is equipped with a 150 mm focal length focusing lens. The combination with a 100 µm fiber ca ble core diameter offers continuous ad justment of spot size ranging from 120 to 320 µm. Furthermore, the wide adjust ment range of the focus position and fo cus diameter offered by the BIMOFSC allows for cutting a broad variety of mate rials with thicknesses up to 25 mm.The investigated cutting tests have been conducted with Teradiode's 4 kW direct diode laser named Terablade. Its wavelength is designed at 970 nm which is shorter than the typical wavelengths of disk lasers (1030 nm) and fiber lasers (1070 nm).Besides different wavelengths, the fiber lasers and diode lasers can differ in beam profile. Fig. 2 shows that both beams have only slight differences at the focus position. Propagating into the near field area, a vast difference in beam profile becomes obvious. While the beam of the fiber laser propagates in a Gaussian like manner, the beam of the diode laser starts to form a TEM 01 mode at two Rayleigh lengths (z R = 5.5 mm for magnification...

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Fibre laser piercing of mild steel – The effects of power intensity, gas type and pressure

Cited by 15 publications

References 15 publications

Influence of Process Parameters in Laser Piercing

Influence of Process Parameters in Laser Piercing

Laser Cutting, Drilling, and Piercing

Laser Cutting Head for High‐Brightness Lasers

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