Non-Distractive Testing by Nanosecond Nd: Yag Laser Technique as Alternative Method to Find Nano -ZnO/Al Properties

Abstract

Purpose Aluminum alloy is widely used in automotive and aircraft due to supper properties such as low density, high strength-to-weight ratio, high corrosion resistance, good impact resistance, good thermal conductivity, excellent castability, and high wear resistance, etc., mechanical properties enhanced by controlling of additional materials, alloying elements, casting process parameters, solidify rates, heat treatments. The paper describes ‘Non-destructive testing (NDT)’ as a material testing method that is less damaging or inducing helpfulness to give information about a material or component. Methods An experimental study employing the laser shock wave technique is performed to examine the physical characteristics of Aluminum before and after covering its surface with ZnO nanoparticles and compare it with the classical testing technique. The NDT experimental data depends on studying high-resolution optical microscopy images by studying the track effect induced by different energy of nanosecond Nd-YAG laser; the shock wave plays a vital role in causing atomic excitation. Results The time duration of the applied laser-induced shock wave is close to the laser pulse for the Al before coating; it decreased after being covered Al by nano ZnO dissolved in water and ethanol medium due to confinement to the surface by a transparent layer; average shock pressures are (5.6, 26,26.12 ) GPa for Al, ZnO dissolved in water /Al, and ZnO dissolved in ethanol /Al, respectively, the mechanical properties results and behaviors of NDT by LSP are comparable to the classical methods (Tensile test and Vicker hardness). The strain and hardness increased after overlaying Al with ZnO nanoparticles while decreasing the Young modulus; the hardness increased by about 4.4 after depositing n-ZnO dissolved in ethanol on Al. The zinc oxide particles deposited on aluminum may also act as a dopant, changing the aluminum's electrical properties, lowering electrical resistivity, and increasing electrical current. Conclusions Dependent on NDLT and classical results, the NDLT results have good agreement with classical methods; it is a good technique employed as an alternative method to find acoustic material properties and mechanical properties; NDLT is a suitable, precision, accurate, cheaper, and non-distractive manner applied to examine the acoustic properties of different materials in the future.

Laser Induced Shock Wave Studies of Aluminum Metal

“…The temperature rise against laser intensity is shown in Fig. (3). We can see the increasing temperature with laser intensity according to equation (1); when the intensity increases above 10 GW/cm 2 , aluminum melting occurs, where the melting point of aluminum is 660.3 °C [9].…”

“…The ionization process involves removing or adding electrons to the atoms or molecules, creating charged particles. The plasma, consisting of ionized particles, can exhibit a slightly conical or cylindrical shape due to the dynamics of the shock wave and the interaction with the surrounding environment [3][4][5][6][7][8].…”

“…A0 represents the laser spot area and A laser area on the material. There are different types of acoustic waves, acoustic wave velocity relation with (E) Young's Modulus given by [3,15]:…”

“…These nonlinear effects can increase strain with increased shock pressure [32]. The negative strain for high shock pressure refers to the compressed effect on aluminum at this pressure value [3]. Two methods are used to measure the stress: by employing LSP Tanique as illustrated in Fig.…”

“…The shock wave can also cause the ejection of small particles or debris from the surface of the aluminum; the characteristics of the laser-induced shock wave, such as its amplitude, duration, and spatial distribution, depend on factors such as the laser energy, pulse duration, spot size, and the optical and mechanical properties of the aluminum. These parameters can be adjusted to control and optimize the desired effects on the aluminum material [3]. Applications of laser-induced shock waves in aluminum processing include material shaping, surface modification, and surface cleaning.…”