Shinichiro Masuno

Experimental investigation of CFRP ablation with UV and N-IR nanosecond lasers

A carbon fiber reinforced plastic (CFRP) is widely used for automobile, aircraft and so on, because of high strength, lightweight and weather resistance. The cutting of CFRP is difficult since it was composed of complex matrix of carbon fiber and epoxy resin. The laser processing is suitable way to machining tool for CFRP. By applying the laser cutting of CFRP, the epoxy resin was quickly evaporated before the carbon fiber cut, which was caused formation of heat affected zone (HAZ). It is required to decrease the HAZ.In this study, nanosecond lasers at UV and IR were employed to cut the CFRP. The ablation plume of CFRP was observed by spectrometer and laser microscope analysis was conducted to evaluate the HAZ. The results revealed that the HAZ formation depended on the laser wavelength. The HAZ of UV laser became smaller than that of IR laser.A carbon fiber reinforced plastic (CFRP) is widely used for automobile, aircraft and so on, because of high strength, lightweight and weather resistance. The cutting of CFRP is difficult since it was composed of complex matrix of carbon fiber and epoxy resin. The laser processing is suitable way to machining tool for CFRP. By applying the laser cutting of CFRP, the epoxy resin was quickly evaporated before the carbon fiber cut, which was caused formation of heat affected zone (HAZ). It is required to decrease the HAZ.In this study, nanosecond lasers at UV and IR were employed to cut the CFRP. The ablation plume of CFRP was observed by spectrometer and laser microscope analysis was conducted to evaluate the HAZ. The results revealed that the HAZ formation depended on the laser wavelength. The HAZ of UV laser became smaller than that of IR laser.

Analysis of laser ablation dynamics of CFRP in order to reduce heat affected zone

A carbon fiber reinforced plastic [CFRP], which has high strength, light weight and weather resistance, is attractive material applied for automobile, aircraft and so on. The laser processing of CFRP is one of suitable way to machining tool. However, thermal affected zone was formed at the exposure part, since the heat conduction property of the matrix is different from that of carbon fiber. In this paper, we demonstrated that the CFRP plates were cut with UV nanosecond laser to reduce the heat affected zone. The ablation plume and ablation mass were investigated by laser microscope and ultra-high speed camera. Furthermore, the ablation model was constructed by energy balance, and it was confirmed that the ablation rate was 0.028 μg/ pulse in good agreement with the calculation value of 0.03 μg/ pulse.

Development of high intensity blue diode laser system for materials processing (Conference Presentation)

High intensity blue diode laser system has been developed for materials processing of especially difficult processing material such as copper. A blue diode laser has an advantage in materials processing of copper since it has a higher absorption rate than traditional lasers whose wavelengths are in infrared region. A blue laser light with the power of 100 W and wavelength of 445 nm could be output from an optical fiber whose core diameter and NA were 100 m and 0.22 since high efficiency coupling of blue lasers emitted from laser diodes using an optical fiber with the core diameter of 100 m was achieved in this system. The intensity of 1.3 x 106 W/cm2 on the substrate was easily obtained at the output power of 100 W and the laser spot diameter of 100 m. The blue laser has already been applied to welding and additive manufacturing. In thermal heat welding, welding of a thin copper plate and a stainless steel pipe was completed. Laser metal deposition (LMD), which was a technology of additive manufacturing, with pure copper powders was performed using the blue laser. The blue laser was also installed in a 3D printing equipment using copper powders based on selective laser melting (SLM) method of additive manufacturing. The performance of the blue laser in materials processing experiments of welding, LMD and SLM in addition to its characteristics and the difference between those experimental results with the blue laser and the traditional infrared diode laser are reported.

Experimental study on Ti alloy plate fabrication by vacuum selective laser melting

We demonstrated that a Ti-6Al-4V plate, which is clinically used for artificial bone and hard tissue implant in human body because of their light and biocompatibility, were fabricated by SLM process in vacuum. The chamber’s pressure was set to 1.0×10-3 Pa to prevent the Ti64 powder from oxidizing. The base plate of the powder bed was vertically dropped in determined steps, and Ti64 powder supplied from the powder feeder was then smoothed by a roller on top of the powder bed. The single-mode fiber laser irradiated and melted the powder bed to make a molten pool in order to form 2D metallic structures In order to investigate the laser melting and solidification dynamics, a process of Ti 64 plate fabrication was captured by high speed video camera. It was also determined that crystal orientation was evaluated with X-ray diffraction (XRD) and energy dispersive X-ray (EDX) spectroscopy From EDX analysis, the chemical compounds were not changed from powder to fabricated sample. And it was recorded from the powder peaks of α (1011), α (0002), α (1010), and α (1012) that the crystal orientation is composed mainly of martensitic alpha by XRD analysis. Diffraction peaks corresponding to β (110) were detected in vacuum SLM processed samples.

Experimental investigation of CFRP cutting with nano second laser under air and Ar gas ambience

A carbon fiber reinforced plastic (CFRP) is widely used for automobile, aircraft and so on, because of having high strength, lightweight and weather resistance. A laser is one of useful tools for cutting CFRP. However, a matrix evaporated zone (MEZ) is formed around the laser irradiation area since heat property of the resin is different from that of carbon fiber. It is required for optimizing the laser processing condition to minimize the MEZ. In our experiment, the CFRP plate was cut with a nanosecond laser under air and Ar gas ambience. The ambient gas is an important factor for reduction of MEZ since formation of MEZ might be caused due to an oxidization of carbon fiber and epoxy resin. In order to evaluate the oxidization, spectroscopic analysis was carried out to investigate an ablation plume under air and Ar gas. Furthermore, a surface on CFRP plate was observed with a scanning electron microscope (SEM). As the results, the cutting quality for argon is better than that for air, and the MEZ for Ar gas is smaller than than that for air.

Experimental investigation on crystal orientation of Ti6Al4V plate fabricated by vacuum SLM process

Ti6Al4V (Ti64) plate was fabricated from powders in vacuum at 10−2 Pa by selective laser melting (SLM) method with single mode fiber laser. Ti64 has a crystal orientation of alpha α + β type. In order to investigate the crystal orientation, a X-ray diffraction in continuous scanning mode and an energy dispersive X-ray spectroscopy were conducted. From the results, it can be found that at the powder, the peak of α (1011), α (0002), α (1010) and α(1012) crystal orientations is detected to be composed mainly of martensitic alpha. Diffraction peaks corresponding to β(110) were detected in vacuum SLM processed samples.Ti6Al4V (Ti64) plate was fabricated from powders in vacuum at 10−2 Pa by selective laser melting (SLM) method with single mode fiber laser. Ti64 has a crystal orientation of alpha α + β type. In order to investigate the crystal orientation, a X-ray diffraction in continuous scanning mode and an energy dispersive X-ray spectroscopy were conducted. From the results, it can be found that at the powder, the peak of α (1011), α (0002), α (1010) and α(1012) crystal orientations is detected to be composed mainly of martensitic alpha. Diffraction peaks corresponding to β(110) were detected in vacuum SLM processed samples.

High-quality cutting of CFRP with 150W pulse fiber laser under control ambient gas

CFRP were cut with high power pulse fiber laser. A CFRP plate was irradiated with laser light from a pulse fiber laser with an average power of 150 W, repetition rate of 1MHz and pulse width of 10ns or 0.4ns. The wavelength of laser light was 1064 nm. A galvanometer scanner was used as the processing head for high speed scanning of the pulsed laser light. After laser irradiation heat affected zone was investigated with SEM. Processing speed and HAZ for pulse width of 10 ns were 3.54 mm/s and 53 µm bigger than that for 0.4 ns to processing speed 2.58 m/s and HAZ of 18 µm respectively. The results indicated pulse width depended on processing speed and HAZ.CFRP were cut with high power pulse fiber laser. A CFRP plate was irradiated with laser light from a pulse fiber laser with an average power of 150 W, repetition rate of 1MHz and pulse width of 10ns or 0.4ns. The wavelength of laser light was 1064 nm. A galvanometer scanner was used as the processing head for high speed scanning of the pulsed laser light. After laser irradiation heat affected zone was investigated with SEM. Processing speed and HAZ for pulse width of 10 ns were 3.54 mm/s and 53 µm bigger than that for 0.4 ns to processing speed 2.58 m/s and HAZ of 18 µm respectively. The results indicated pulse width depended on processing speed and HAZ.

Nanosecond laser processing of CFRP in Ar gas ambience for HAZ reduction

A cross type of carbon fiber reinforced plastic (CFRP) plate, which composed of a carbon fiber and an epoxy resin, was put on the X-Y stage in the processing chamber. Ar gas was filled at 0.1 MPa in the chamber after exhaust at 1Pa. In this condition, the laser was irradiated the CFRP passing the attenuator for adjusting the laser intensity. After laser irradiation, the matrix evaporated zone (MEZ) was investigated with a confocal laser microscope. In Ar gas ambience, the MEZ was occurred few delamination area from 1.0 × 108 to 1.0 × 1010 W/cm2 of the laser fluence. The results revealed that the laser cutting of the CFRP in Ar gas ambience might be a useful method to suppression of the oxidization of the carbon fiber.A cross type of carbon fiber reinforced plastic (CFRP) plate, which composed of a carbon fiber and an epoxy resin, was put on the X-Y stage in the processing chamber. Ar gas was filled at 0.1 MPa in the chamber after exhaust at 1Pa. In this condition, the laser was irradiated the CFRP passing the attenuator for adjusting the laser intensity. After laser irradiation, the matrix evaporated zone (MEZ) was investigated with a confocal laser microscope. In Ar gas ambience, the MEZ was occurred few delamination area from 1.0 × 108 to 1.0 × 1010 W/cm2 of the laser fluence. The results revealed that the laser cutting of the CFRP in Ar gas ambience might be a useful method to suppression of the oxidization of the carbon fiber.

Dependence of cutting carbon fiber reinforced plastics with nanosecond laser on the laser wavelength and oxygen concentration of the air

Carbon fiber reinforced plastics (CFRP) is a kind of advanced light-weight materials. CFRP is used in various transport equipment in order to increase fuel economy. Laser cutting is one of useful technologies for cutting CFRP. However, heat affected zone (HAZ) is formed at laser irradiation area since the heat conduction property of the matrix is different from that of carbon. In our experiments, we investigated the dependence of HAZ on oxygen concentration by irradiating nanosecond laser in the chamber in argon gas, which reduces oxygen concentration, and in the air. The results suggested that the laser cutting of the CFRP in argon gas might be a useful method to reduce heat affected zone due to suppression of the oxidization of the carbon fibers.Carbon fiber reinforced plastics (CFRP) is a kind of advanced light-weight materials. CFRP is used in various transport equipment in order to increase fuel economy. Laser cutting is one of useful technologies for cutting CFRP. However, heat affected zone (HAZ) is formed at laser irradiation area since the heat conduction property of the matrix is different from that of carbon. In our experiments, we investigated the dependence of HAZ on oxygen concentration by irradiating nanosecond laser in the chamber in argon gas, which reduces oxygen concentration, and in the air. The results suggested that the laser cutting of the CFRP in argon gas might be a useful method to reduce heat affected zone due to suppression of the oxidization of the carbon fibers.

Observation of cross-section surface after cutting of CFRP with UV laser

CFRP (Carbon Fiber Reinforced Plastic) is a new material featuring light and high strength. It has been expectedas a material for automobile and airplane productions since the weight of them are reduced by using CFRP. Laser is one of useful cutting tools of CFRP. However, in case of cutting CFRP by using a laser, HAZ (Heat Affected Zone) is formed at laser irradiation area. Strength of CFRP is lowered by HAZ formed. Laser wavelengthis an important factor for reducing HAZ. Laser absorption rates of a carbon fiber and a resin depend on laser wavelength. The size of HAZ might be varied due to the absorption rates of carbon fiber and resin. However, suitable laser wavelength for reduction of HAZ is not still cleared. A CFRP was cross-ply laminates molded with epoxy resin in this experiment. The CFRP plate was cut with a UV nanosecondlaser. The pulse width and the repetition rate were 6ns and 10 Hz, respectively. The surface and the cross-section of the CFRP plate were observed with scanning electron microscop...