Development of High-Performance Polycrystalline CVD Diamond Coated Cutting Tool Edge With Femtosecond Laser

2020 ◽  
Author(s):  
Xiaoxu Liu ◽  
Kohei Natsume ◽  
Satoru Maegawa ◽  
Fumihiro Itoigawa
Keyword(s):  
Surface Modification ◽  
Femtosecond Laser ◽  
Pulse Laser ◽  
Laser Fluence ◽  
High Performance ◽  
Short Pulse ◽  
Cvd Diamond ◽  
Diamond Surface ◽  
Nanosecond Laser ◽  
Tool Edge

Abstract To realize the high performance of CVD diamond coated tools, a tool edge shaping process named pulse laser grinding (PLG) was developed with short pulse laser in our group previously. In this study, femtosecond laser was innovatively to be used to conduct the PLG process, since femtosecond laser is famous for its less thermal impact and some newly reported surface modification effect. The results show that PLG processing under high laser fluence of femtosecond laser could achieve roundness around 1 μm, which is similar to that of conventional PLG process with nanosecond laser, although the roughness of processed surface has been worse due to the redeposited debris. Furthermore, an interesting phenomenon has been confirmed again that under low laser fluence irradiation of femtosecond laser, the CVD diamond surface shows improved crystallinity of diamond structure. Based on this, a two-step tool edge processing method was proposed, which could realize the edge shaping and surface modification together with one laser processor. And the results show that the processed tool edge with much less edge roundness and surface roughness, and the tip part with better diamond crystallinity, indicating that sharper and hardness tool edge could be possibly to be realized with femtosecond laser.

X-ray characterization of short-pulse laser illuminated hydrogen storage alloys having very high performance

2015 ◽  
Author(s):  
Hiroyuki Daido ◽  
Hiroshi Abe ◽  
Takahisa Shobu ◽  
Takuya Shimomura ◽  
Shinnosuke Tokuhira ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Pulse Laser ◽  
High Performance ◽  
Short Pulse ◽  
Hydrogen Storage Alloys ◽  
X Ray ◽  
Short Pulse Laser ◽  
Very High

scholarly journals Laser-induced ablation of tantalum in a wide range of pulse durations

2020 ◽  
Vol 126 (9) ◽  
Author(s):  
Steffen Mittelmann ◽  
Jannis Oelmann ◽  
Sebastijan Brezinsek ◽  
Ding Wu ◽  
Hongbin Ding ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Laser Pulse ◽  
Femtosecond Laser ◽  
Pulse Duration ◽  
Laser Fluence ◽  
Crater Depth ◽  
Nanosecond Laser ◽  
Threshold Fluence ◽  
Wide Range ◽  
Laser Systems

Abstract We present data and analysis of the laser-induced ablation of pure tantalum (Ta, $$Z=73$$ Z = 73 ). We have identified different physical regimes using a wide range of laser pulse durations. A comparison of the influence of strongly varying laser pulse parameters on high-Z materials is presented. The crater depth caused by three different laser systems of pulse duration $${\varDelta }\tau _1=5\,\mathrm {ns}$$ Δ τ 1 = 5 ns and wavelength $$\lambda _1=1064\,\mathrm {nm}$$ λ 1 = 1064 nm , $${\varDelta }\tau _2=35\,\mathrm {ps}$$ Δ τ 2 = 35 ps , $$\lambda _2=355\,\mathrm {nm}$$ λ 2 = 355 nm and $${\varDelta }\tau _3=8.5\,\mathrm {fs}$$ Δ τ 3 = 8.5 fs , $$\lambda _3=790\,\mathrm {nm}$$ λ 3 = 790 nm are analyzed via confocal microscopy as a function of laser fluence and intensity. The minimum laser fluence needed for ablation, called threshold fluence, decreases with shorter pulse duration from $$1.10\,\mathrm {J/cm}^2$$ 1.10 J / cm 2 for the nanosecond laser to $$0.17\,\mathrm {J/cm}^2$$ 0.17 J / cm 2 for the femtosecond laser.

Femtosecond Laser Ablation of Titanium and Silicon

2000 ◽  
Author(s):  
Mengqi Ye ◽  
Costas P. Grigoropoulos
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Laser Fluence ◽  
Laser System ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Femtosecond Laser Irradiation ◽  
Nanosecond Laser ◽  
Iccd Camera ◽  
Plume Emission

Abstract Femtosecond laser ablation of titanium and silicon samples has been studied via time-of-flight (TOF), emission spectroscopy and microscopy measurement. Laser pulses of around 100 fs (FWHM) at λ = 800 nm were delivered by a Ti:sapphire femtosecond laser system. A vacuum chamber with a base pressure of 10−7 torr was built for ion TOF measurement. These ion TOF spectra were utilized to determine the velocity distribution of the ejected ions. While nanosecond laser ablation typically generates ions of a few tens of eV, femtosecond laser irradiation even at moderate energy densities can produce energetic ions with energies of up to a few keV. The most probable energy of these fast ions is proportional to the laser fluence. The structure and number of peaks of the TOF spectra varies with the laser fluence. Images of plume emission were captured by an intensified CCD (ICCD) camera. The plume emission spectrum was analyzed by a spectrometer. Laser ablated craters were measured by an interferometric microscope and a scanning electron microscope (SEM). Ablation yield was expressed as a function of laser fluence, and number of shots.

Fundamental Research on Via Processing by Using Short Pulse Laser in SiC

2013 ◽  
Author(s):  
Naoki Iwatani ◽  
Hong Duc Doan ◽  
Kazuyoshi Fushinobu
Keyword(s):  
Pulse Laser ◽  
Laser Fluence ◽  
Optimal Parameter ◽  
Short Pulse ◽  
Etching Rate ◽  
Water Film ◽  
High Energy ◽  
Pulse Number ◽  
Short Pulse Laser ◽  
Sic Wafer

Laser drilling of silicon carbide (SiC) wafer in air (dry ablation) and underwater by using ns pulsed infrared (1064 nm) Nd: YAG laser is investigated. In order to suggest optimal parameters of via processing in SiC wafer, the effects of pulse number, laser fluence, water film thickness, and focus position are evaluated. As compared with dry ablation vias, decreasing etching rate, increasing via diameter, and generation of cracks in high-energy regime are observed in liquid-assisted processing. However, it is found that it can create vias without debris, HAZ, cracks. Also, optimal parameter set for infrared pulse laser processing under water is found to be the laser fluence of less than 10 J/cm2 and water thickness of 1mm.

Thermal Process of Drilling for Metal Thin Films Using Femtosecond Laser

2015 ◽  
Vol 764-765 ◽  
pp. 102-106
Author(s):  
Ching Yen Ho ◽  
Chung Ma ◽  
Yu Hsiang Tsai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Femtosecond Laser ◽  
Laser Fluence ◽  
Thermal Process ◽  
Short Pulse ◽  
Laser Drilling ◽  
Drilling Depth ◽  
Metal Thin Films ◽  
Metal Thin Film

The femtosecond laser drilling for metal thin film is theoretically investigated in this paper. Femtosecond laser patterning of metal thin films is of technological significance because the fabrication of electrodes or metallization lines is a key process commonly required in the manufacturing of modern electronic devices. A femtosecond pulsed laser has a temporally short pulse that does not cause significant heat conduction in the material. This property of femtosecond laser pulse drilling makes sub-micron machining achievable with laser irradiation. Considering vaporization as the mechanism of the material removal, this paper employs two-temperature model to analyze the thermal process for femtosecond laser drilling of metal thin film. The variations of the drilling rate and squared diameter with laser fluence are compared with the available experimental data. This study also analytically validates that the drilling depth per pulse is governed by the optical penetration depth for low laser fluences and the squared crater diameter is linearly in proportion to the logarithm of laser fluence.

scholarly journals Development of High-Performance Polycrystalline CVD Diamond-Coated Cutting Tools Using Femtosecond Lasers

2021 ◽  
Vol 15 (4) ◽  
pp. 413-421
Author(s):  
Xiaoxu Liu ◽  
◽  
Osamu Konda ◽  
Hiroko Furuhashi ◽  
Kohei Natsume ◽  
...  
Keyword(s):  
High Performance ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Laser Parameters ◽  
Shaping Process ◽  
Tool Edge ◽  
Coated Tool ◽  
Fs Laser ◽  
Diamond Peak

Pulse laser grinding (PLG), an edge-shaping process, was developed previously to implement high-performance cutting tools. In this study, two femtosecond (fs) lasers with wavelengths of 1045 nm and 257 nm were used to conduct PLG on chemical vapor deposited (CVD) diamond-coated tool edges, as the fs laser is reported to have less thermal impact and the potential to improve the material crystallinity. We investigated the effects of the laser parameters on the tool edge formation and microstructural changes. The results show that although the infrared fs laser could – compared to the conventional nanosecond (ns)-laser PLG – naturally suppress surface thermal damage, the roughness of the processed surface remained relatively high with an Rz of 0.21 μm. However, under the optimal laser parameters proposed in this paper, an ultraviolet fs-laser PLG was used to obtain a much smoother edge, reducing Rz to approximately 0.08 μm. Moreover, scanning electron microscopy images indicated that the longitudinal machining marks on the ns-laser-processed surface were significantly reduced, with virtually no attached debris on the surface. Furthermore, from the Raman spectra, a significant increase in the diamond peak intensity was observed, indicating that the crystallinity of the CVD diamond (CVDD) was improved following ultraviolet-fs-laser PLG. These results demonstrate that edge shaping and structural modification of polycrystalline CVDDs can be integrated into ultraviolet-fs-laser PLG.

Surface modification of polycrystalline CVD diamond films with femtosecond laser

2019 ◽  
Author(s):  
Kohei Natsume ◽  
Xiaoxu Liu ◽  
Satoru Maegawa ◽  
Fumihiro Itoigawa ◽  
Shingo Ono ◽  
...  
Keyword(s):  
Surface Modification ◽  
Femtosecond Laser ◽  
Diamond Films ◽  
Cvd Diamond
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