The effect of number of pulses of pulsed laser on materials is studied analytically, different pulses has been used with the same delay time. The depth of possible damage to the surface of copper and titanium as well as depth of the crater to both materials were considered in this study. The study revealed that linear model is only possible when estimating depth of possible damage for copper material, this means that the depth of possible damage increases with the increment of number of laser pulses .As for titanium material, it is found the relationship is nonlinear. The depth of possible damage of titanium and copper is not the same, and copper seems to be more predictable than titanium.
Background: Surface treatment of machined dental zirconia for enhancement of the adhesion to resin cement, using Er,Cr:YSGG Laser. Materials and Methods: Total number of 42 zirconia disc specimens (9 mm diameter, and 2 mm height) was sintered according to the manufacturer instruction. They are divided into six groups, each group of seven samples. Laser groups (Experiment parameters) were depend on laser total irradiation time, pulse duration, and power. Group (A): 20 sec., 60 µs pulse duration. Group (B): 30 sec., 60 µs pulse duration. Group (C): 40 sec., 60 µs pulse duration. Group (D): 20 sec., 700 µs pulse duration. Group (E): 30 sec., 700 µs pulse duration, with different powers used (1, 1
... Show MoreBaTiO3 thin films have been deposited on Si (111) and glass substrates by using pulsed laser deposition technique. The films were characterized by using X-ray diffraction, atomic force microscope and optical transmission spectra. The films growth on Si after annealing at 873K showed a polycrystalline nature, and exhibited tetragonal structure, while on glass substrate no growth was noticed at that temperature. UV-VIS transmittance measurements showed that the films are highly transparent in the visible wavelength region and near-infrared region for sample annealing on glass substrate. The optical gap of the film were calculated from the curve of absorption coefficient (αhν) 2 vs. hν and was found tobe 3.6 eV at substrate temperature 5
... Show MoreThis paper presents the theoretical and experimental results of drilling high density
polyethylene sheet with thickness of 1 mm using millisecond Nd:YAG pulsed laser. Effects of laser
parameters including laser energy, pulse duration and peak power were investigated. To describe and
understand the mechanism of the drilling process Comsol multiphysics package version 4.3b was used to
simulate the process. Both of the computational and experimental results indicated that the drilling
process has been carried out successfully and there are two phases introduced in the drilling process,
vaporization and melting. Each portion of these phases depend on the laser parameters used in the
drilling process
In this paper, the productions of gallium oxide (Ga2O3) nanoparticles were achieved via using the Nd: YAG laser deposition method with a fundamental wavelength (1064 nm). These nanoparticles were characterized by using different methods such as X-ray diffractometer (XRD), atomic force microscopy (AFM) and Ultraviolet–visible (UV–vis) spectroscopy. To examine the effects of laser energy on the properties of nanoparticles, the experimental results and theoretical considerations were prepared by the effective method of pulse laser deposition. The synthesis of Ga2O3NPs) was achieved with different ranges of energies (500 to 900 mJ). Average crystallite sizes of the synthesized nanopar
... Show MoreThis study investigated the effect of applying an external magnetic field on the characteristics of laser-induced plasma, such as its parameters plasma, magnetization properties, emission line intensities, and plasma coefficients, for plasma induced from zinc oxide: aluminum composite (ZO:AL) at an atomic ratio of 0.3 %. Plasma properties include magnetization and emission line intensities. The excitation was done by a pulsed laser of Nd:YAG with 400 mJ energy at atmospheric pressure. Both the electron temperature and number density were determined with the help of the Stark effect principle and the Boltzmann-Plot method. There was a rise in the amount of (ne) and (Te) that was produced
... Show MoreIn this paper, the fundamental harmonic of a Nd:YAG laser (Q-switched 1064nm wavelength, 1 Hz repetition rate and 9 ns pulse duration) has been used for the ablation of cadmium samples in air at atmospheric pressure and the generation of the cadmium plasma. The experimentally observed lines of cadmium plasma emission have been used to calculate the plasma parameters such as (electron temperature (TReR), electron density (nReR), Debye length (λRDR) and plasma frequency (ωRpR)). Line pair ratio of neutral species have been used for the electron temperature and electron density measurements. Plasma parameters were studied as a functions of laser pulse energy.
In this work; Silicon dioxide (SiO2) plasma plume was prepared by laser induced plasma (LIP). The electron number density, plasma frequency and Debye length were calculated by reading the data of I-V curve of Langmuir probe which was used as a diagnostic method of measuring plasma properties. Pulsed Nd:YAG laser was used for measuring the electron number density of SiO2 plasma plume under vacuum environment with varying both vacuum pressure and axial distance from the target surface. Some physical properties of the plasma generated such as electron density, plasma frequency and Debye length have been measured experimentally and the effects of vacuum pressure and Langmuir probe distance from the target were studied on those variables. An
... Show MorePure cadmium oxide films (CdO) and doped with zinc were prepared at different atomic ratios using a pulsed laser deposition technique using an ND-YAG laser from the targets of the pressed powder capsules. X-ray diffraction measurements showed a cubic-shaped of CdO structure. Another phase appeared, especially in high percentages of zinc, corresponding to the hexagonal structure of zinc. The degree of crystallinity, as well as the crystal size, increased with the increase of the zinc ratio for the used targets. The atomic force microscopy measurements showed that increasing the dopant percentage leads to an increase in the size of the nanoparticles, the particle size distribution was irregular and wide, in addition, to increase the surfac
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