Influence of surface morphology on processing of C/SiC composites via femtosecond laser

AbstractSilicon surface morphology induced by a femtosecond laser pulse at near-threshold fluences in water environment is investigated by means of atomic-force microscopy (AFM). With increasing fluence, the silicon surface transforms into nanoscale ring-shaped and blister structures, as well as smooth and nanostructured microcraters with a minimum depth of 1 nm. The formation of starlike patterns imprinted at the surface of microcraters at fluences above the ablation threshold is observed.

Download Full-text

Machining millimeter-scale deep holes in SiCf/SiC material using femtosecond laser filamentation effect

Materials Science Advanced Composite Materials ◽

10.18063/msacm.v2i1.748 ◽

2018 ◽

Vol 2 (3) ◽

Author(s):

Jie Zhao 1,2 ◽

Wenjun Wang 1,2 ◽

Ruijia Wang 1,2 ◽

Jianlei Cui 1,2

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Femtosecond Laser ◽

Surface Morphology ◽

Peak Power ◽

Processing Time ◽

Ablation Threshold ◽

Focus Position ◽

Laser Focus ◽

Scanning Electron

A 3.5 mm thick SiCf/SiC material was drilled in air environment using a femtosecond laser filament effect. The surface morphology of deep micropores was observed by scanning electron microscopy and the depth and profile of the pores were observed using μm-CT. The variation of entrance diameter, exit diameter and depth variation with laser focus position and processing time was further analyzed. The results showed that as the processing time of femtosecond laser increases, the ablation threshold of the material reached saturation. The exit and entrance diameter also stopped increasing and the aperture tend to saturate. The focus entered the interior of the material, allowing the location of the peak power near the surface of the material. So the entrance aperture was of good quality and the exit aperture was round.

Download Full-text

Effect of mass transfer channels on flexural strength of C/SiC composites fabricated by femtosecond laser assisted CVI method with optimized laser power

Journal of Advanced Ceramics ◽

10.1007/s40145-020-0433-2 ◽

2021 ◽

Vol 10 (2) ◽

pp. 227-236

Author(s):

Jing Wang ◽

Liyang Cao ◽

Yunhai Zhang ◽

Yongsheng Liu ◽

Hui Fang ◽

...

Keyword(s):

Mass Transfer ◽

Femtosecond Laser ◽

Chemical Vapor ◽

Ceramic Matrix Composites ◽

Strengthening Mechanism ◽

Chemical Vapor Infiltration ◽

Matrix Composites ◽

Dense Band ◽

Sic Composites ◽

Transfer Channels

AbstractIn this study, femtosecond laser assisted-chemical vapor infiltration (LA-CVI) was employed to produce C/SiC composites with 1, 3, and 5 rows of mass transfer channels. The effect of laser machining power on the quality of produced holes was investigated. The results showed that the increase in power yielded complete hole structures. The as-obtained C/SiC composites with different mass transfer channels displayed higher densification degrees with flexural strengths reaching 546 ± 15 MPa for row mass transfer channel of 3. The strengthening mechanism of the composites was linked to the increase in densification and formation of “dense band” during LA-CVI process. Multiphysics finite element simulations of the dense band and density gradient of LA-CVI C/SiC composites revealed C/SiC composites with improved densification and lower porosity due to the formation of “dense band” during LA-CVI process. In sum, LA-CVI method is promising for future preparation of ceramic matrix composites with high densities.

Download Full-text

Surface morphology and phase transformations of femtosecond laser-processed sapphire

Applied Surface Science ◽

10.1016/j.apsusc.2013.10.026 ◽

2014 ◽

Vol 288 ◽

pp. 313-323 ◽

Cited By ~ 13

Author(s):

R. Vilar ◽

S.P. Sharma ◽

A. Almeida ◽

L.T. Cangueiro ◽

V. Oliveira

Keyword(s):

Femtosecond Laser ◽

Surface Morphology ◽

Phase Transformations

Download Full-text

Effect of the surface microstructure ablated by femtosecond laser on the bonding strength of EBCs for SiC/SiC composites

Optics Communications ◽

10.1016/j.optcom.2018.04.055 ◽

2018 ◽

Vol 424 ◽

pp. 137-144 ◽

Cited By ~ 27

Author(s):

Zhaoyang Zhai ◽

Wenjun Wang ◽

Xuesong Mei ◽

Ming Li ◽

Jianlei Cui ◽

...

Keyword(s):

Femtosecond Laser ◽

Bonding Strength ◽

Surface Microstructure ◽

Sic Composites

Download Full-text

Femtosecond Laser-Induced Silicon Surface Morphology in Water

Volume 10: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B, and C ◽

10.1115/imece2008-67923 ◽

2008 ◽

Author(s):

Yukun Han ◽

Cheng-Hsiang Lin ◽

Hai-Lung Tsai

Keyword(s):

Femtosecond Laser ◽

Surface Morphology ◽

Surface Quality ◽

Silicon Wafer ◽

Silicon Surface ◽

Periodic Structures ◽

Industrial Applications ◽

Silicon Surfaces ◽

Wafer Surface ◽

Laser Parameter

This article investigates the use of femtosecond laser induced surface morphology on silicon wafer surface in water confinement. Unlike irradiation of silicon surfaces in the air, there are no laser induced periodic structures, but irregular roughness is formed when the silicon wafer is ablated under water. The unique discovery of a smoothly processed silicon surface in water confinement under certain laser parameter combinations may help improve laser direct micromachining surface quality in industrial applications.

Download Full-text

Surface Morphology Evolution Induced by Multiple Femtosecond Laser Ablation on 4H-SiC Substrate and Its Application to CMP

ECS Journal of Solid State Science and Technology ◽

10.1149/2.0261712jss ◽

2017 ◽

Vol 6 (12) ◽

pp. P853-P861 ◽

Cited By ~ 3

Author(s):

Chengwu Wang ◽

Syuhei Kurokawa ◽

Toshiro Doi ◽

Julong Yuan ◽

Binghai Lv ◽

...

Keyword(s):

Laser Ablation ◽

Femtosecond Laser ◽

Surface Morphology ◽

Femtosecond Laser Ablation ◽

Morphology Evolution ◽

Surface Morphology Evolution

Download Full-text

Femtosecond laser ablation of brass: A study of surface morphology and ablation rate

Laser and Particle Beams ◽

10.1017/s0263034612000407 ◽

2012 ◽

Vol 30 (3) ◽

pp. 473-479 ◽

Cited By ~ 19

Author(s):

Mohamed E. Shaheen ◽

Brian J. Fryer

Keyword(s):

Laser Ablation ◽

Femtosecond Laser ◽

Surface Morphology ◽

Fine Particles ◽

Femtosecond Laser Ablation ◽

Laser Pulses ◽

Ambient Air ◽

Ablation Rate ◽

Femtosecond Laser Pulses ◽

Nanosecond Laser

AbstractThe interaction of near infrared femtosecond laser pulses with a Cu based alloy (brass) in ambient air at atmospheric pressure and under different laser conditions was investigated. The effects of laser fluence and number of pulses on surface morphology and ablation rate were studied using scanning electron microscopy (SEM) and optical microscopy. Ablation rates were found to rapidly increase from 83 to 604 nm/pulse in the fluence range 1.14–12.21 J/cm2. At fluence >12.21 J/cm2, ablation rates increased slowly to a maximum (607 nm/pulse at 19.14 J/cm2), and then decreased at fluence higher than 20.47 J/cm2 to 564 nm/pulse at 24.89 J/cm2. Large amounts of ablated material in a form of agglomerated fine particles were observed around the ablation craters as the number of laser pulses and fluence increased. The study of surface morphology shows reduced thermal effects with femtosecond laser ablation in comparison to nanosecond laser ablation at low fluence.

Download Full-text