EFFECT OF POWER ON HOLE QUALITY OF UNDERWATER GLASS DRILLING USING CO2 LASER

The aim of this paper to study the effect of power on the drilling of soda lima glass (SLG) using under water laser drilling technique. A 1.15 mm thickness SLG sheets were immersed 1mm below the water surface, then irradiated with CW CO2 laser. The laser parameters used were (24, 25 and 26) W power, (5, 7.5 and 10) sec and exposure time and (1, 2and 3) pulses. Were determined using images for samples and study quality of holes using images. These ones of the dimensional of hole and crack length measured by image j program of the samples, it was watched that hole diameter and the length of cracks could be regulated by the power, time and no. of pulses. When power or pulses were increased, the hole diameter increased. The length of cracks decreased with increased no. of pulses and increased when the power increased. The small hole was 0.469mm found at working power (24) W, five seconds and one pulse for hole diameter. While, the minimum crack length was 0.4mm found at three pulse, five sec. and 24 W power. In addition, the parameters were analyzed statistically using design of expert software, Box Behnken design from surface response methodology and the results were significant

Tailored CuCl2 nanoparticles for glutamine and ammonia biochemical sensing applications

In this study, CuCl2 nanoparticles (NPs) synthesised via pulsed laser ablation in liquid (PLAL) were successfully employed to simultaneously detect glutamine and ammonia, with a limit of detection of 20Â nM and up to 1500Â ppm, respectively. These NPs hold potential for non-invasive diagnosis and monitoring of various health conditions using urine and sweat samples. The sensing mechanism relied on the plasmon peaks of CuCl2 NPs in the UV range (at 300, 363, and 423Â nm), which were used to correlate the levels of glutamine and ammonia concentration with the absorbance. Quasi-spherical CuO and pyramidal CuCl2 NPs were synthesised through laser ablation of Cu powder in liquid IPA and IPA-HCl, respectively. CuCl2 NPs displayed higher ablation efficiency, higher optical absorbance (20-fold), and an 8400-fold increase in colloidal conductivity (0.0005 vs 4.2Â mS/cm) compared to CuO NPs. The NP size distribution ranged broadly from 10Â nm to less than 100Â nm. XPS analysis revealed that ablation in pure IPA resulted in oxidized Cu NPs, while ablation in IPA-HCl liquid medium (12Â nM HCl) led to the formation of a combination of metallic copper and CuCl2 NPs that were more conductive and had higher optical absorbance than their oxidized counterparts

Liquid phase pulsed laser ablation: a route to fabricate different carbon nanostructures

Carbon nanostructures in various forms and sizes, and with different speciation properties have been prepared from graphite by Liquid Phase - Pulsed Laser Ablation (LP-PLA) using a high frequency Nd:YAG laser. High energy densities and pulse repetition frequencies of up to 10 kHz were used in this ablation process to produce carbon nanomaterials with unique chemical structures. Dynamic Light Scattering (DLS), micro-Raman and High-Resolution Transmission Electron Microscopy (HRTEM) were used to confirm the size distribution, morphology, chemical bonding, and crystallinity of these nanostructures. This article demonstrates how the fabrication process affects measured characteristics of the produced carbon nanomaterials. The obtained particle properties have potential use for various applications including biochemical speciation applications

Laser surface cladding of metal parts

Laser surface cladding is a significant process used for improving and altering the surface properties of materials. Examples of these alterations are cladding of bulk materials with stronger and more expensive materials for enhancing the surface wear resistance, hardness, corrosion resistance, or creating magnetic property on non-magnetic material. In this paper, metal samples were laser processed by using the pre-deposited paste-powder method of laser surface cladding. Aluminium of Al6061 alloy and EN3B mild steel were chosen as the substrates, coated with the materials Inconel 718, Nitinol and 316 L stainless steel. A comparison of each of the sample's mechanical properties through specific wear rate and microhardness was conducted. It was found that all samples had improved microhardness compared to that of their substrates. Furthermore, all aluminum base samples had significantly improved wear rates by at least 72%. Microhardness increase of 3.2 and 1.5 times on the Al and steel samples cladded with Inconel and Nitinol respectively. The cross-section of all the processed samples' microstructure was examined under a scanning electron microscope. Results showed the interface of the clad layer, substrate, and a clear heat-affected zone of the mild steel samples

Comparing the surface hardness of mild steel processed with CO₂ and fibre lasers

The microhardness of low carbon mild steel was analysed after surface treatment by using carbon dioxide CO₂ and Fibre laser for comparison. Identical input parameters were used to compare the increase between the as-supplied material hardness and the treated surface. Microhardness testing was used to measure the surface hardness and a scanning electron microscope (SEM) was used to investigate the microstructural changes in the substrate. It was found that the laser scanning speed had a significant effect on the increased surface hardness, while the laser power was a less significant factor. The samples processed with the lower laser fluence of the Fibre laser exhibited a hardness increase of 38% with maximum depth of 200 μm, while those processed by the CO₂ laser exhibited a hardness increase of 41% with a maximum depth of 50 μm. A full design of experiment (DoE) model was modified for the optimization and prediction of the laser hardening process. The processing parameters applied were the laser beam power and the scanning speed

Influence of Exposure Parameters on Nanoliquid-Assisted Glass Drilling Process Using CO₂ Laser

Liquid-assisted laser processing (LALP) is implemented using a 10.6 μm continuous-wave (CW) CO2 laser to drill holes in 1.1 mm thick soda-lime glass substrates fully immersed in a nanoliquid bath. The nanoliquid bath consisted of de-ionized water and carbon nano-particles (CNPs) of different wt.%. The study focuses on the influence of exposure time (TE, [s]), laser beam power (P, [W]) and number of pulses (NP) on resulting geometrical features, namely, crack length (CL, [mm]), inlet diameter (DINLET, [mm]) and exit diameter (DEXIT, [mm]). The processed samples were characterized using an optical microscope. Findings show that LALP with investigated ranges of control parameters TE (0.5–1.5 s), P (20–40 W) and NP (1–6 pulses) led to successful production of drilled holes having CL range (0.141 to 0.428 mm), DINLET range (0.406 to 1.452 mm) and DEXIT range (0.247 to 1.039 mm). It was concluded that increasing TE alone leads to increasing CL, DINLET and DEXIT, while keeping a good balance among the control parameters, especially TE and NP, will result in reduced CL values. Moreover, process statistical models were developed using statistical analysis of variance (ANOVA). These models can be used to further understand and control the process within the investigated ranges of control and response parameters