Aluminum Samples Research Articles

Aluminum and Inorganic Natural Pigment Colored Composites by Powder Metallurgy Forming

Aluminum powder, along with other powders such as steel or stainless steel, is extensively used in powder metallurgy (PM) to produce complex samples with irregular geometric shapes. PM enables the incorporation of fillers to modify the physical, mechanical, or wear properties of aluminum without melting, thereby preventing phase segregation. The novelty of this work lies in the use of inorganic natural pigments (INPs). The primary goal of this study is to produce colored aluminum samples via PM without compromising their mechanical properties. INPs are first characterized to select those with the highest heat resistance. The composites are fabricated with different pigments (10 wt%), formed through uniaxial compaction at 500 MPa, and sintered in a nitrogen atmosphere at 610 °C for 30 min. Density, color, bending strength, and wear are evaluated to identify the most suitable pigment for gas kitchen burners. Mars red, Cobalt blue, and Chrome green pigments provide the best coloration. Dimensional variation is generally less than 1%. The pigments increase the material’s brittleness by 41% to 77%, resulting in a bending modulus increase of up to 160% and deformation reduction of up to 70%. In some cases, intermetallic compounds improve bending strength, as in Al–Chrome green, by 30%. Al–Chrome green exhibits wear resistance comparable to aluminum, with a 40% lower friction coefficient. X-ray diffraction and SEM-EDX confirm AlCr and AlCo intermetallic particles. Thermal stability is verified after 160 heating and cooling cycles without significant material degradation.

An Open-Source Algorithm for Correcting Stress Wave Dispersion in Split-Hopkinson Pressure Bar Experiments.

Stress wave dispersion can result in the loss or distortion of critical high-frequency data during high-strain-rate material tests or blast loading experiments. The purpose of this work is to demonstrate the benefits of correcting stress wave dispersion in split-Hopkinson pressure bar experiments under various testing situations. To do this, an innovative computational algorithm, SHPB_Processing.py, is created. Following the operational run through of SHPB_Processing.py's capabilities, it is used to process test data acquired from split-Hopkinson pressure bar tests on aluminium, sand and kaolin clay samples, under various testing conditions. When comparing dispersion corrected and simple time shifting data obtained from SHPB experiments, accounting for dispersion removes spurious oscillations and improves the inferred measurement at the front of the specimen. The precision of the stress and strain results gathered from its application emphasises its importance through the striking contrast between its application and omission. This has a significant impact on the validity, accuracy and quality of the results. As a result, in the future, this tool can be utilised for any strain rate testing situation with cylindrical bars that necessitates dispersion correction, confinement, or stress equilibrium analysis.

ANALYSIS OF THE EFFECT OF ION IMPLANTATION ON CORROSION RESISTANCE AND CONTAMINATION OF HEAT TRANSFER SURFACES

BACKGROUND: the article addresses the problem of improving the energy efficiency and durability of heat exchange equipment. Particular attention is paid to improving the characteristics of heat exchange surfaces of heat exchangers, which play a key role in many industries. The problems of pollution and corrosion of heat exchange surfaces and the causes that led to them are discussed. AIMS: analysis of the effect of ion implantation on the contamination and corrosion resistance of heat exchange surfaces of heat exchange equipment MATERIALS AND METHODS: Within the framework of this study, comparative analysis methods were used to record changes in the composition of the surface layer of the samples under study. Microhardness studies were carried out in the direction from the surface to the depth of the test sample using the Neophot-2 instrument on transverse metallographic sections cut perpendicular to the implantation. RESULTS: During the study, data were obtained on changes in microhardness of aluminum samples after nitrogen implantation, as well as on changes in the structural composition of surface layers and increased resistance to corrosion, contamination, and prolonged exposure to surfactants. CONCLUSIONS: As a result of the work, it can be said that a decrease in energy efficiency due to contamination of heat exchange surfaces is more pronounced in heat exchangers in which a high value of the heat transfer coefficient was initially laid down. Ion implantation not only increases the microhardness and wear resistance of materials, but also prevents the appearance of an oxide film, which in turn reduces the contamination of the heat exchange surface, and also makes the heat exchange surface less susceptible to prolonged exposure to surfactants

VALIDATION OF CORROSION STATUS OF SOME ROOFING SHEETS UTILIZED IN GOMBE METROPOLIS

The study was aim at investigation the level of corrosion on roofing sheets utilized in Gombe where acid and alkaline medium immersion test of 25 days showed that light zinc (0.15 mm) sample decreased in weight from 0.03g to 0.04 g while the 2.0mm zinc decreased in weight range of 0.01g to 0.04 g in the alkaline solution. Samples of thick aluminum (5.5 mm) and light aluminium(4.5mm) showed insignificant weight range 0.0g to 0.03 g after immersion in alkaline. In acidic medium both light and thick zinc showed greater weight lost 0.05g to 0.08g. However both the thick and light aluminium showed loss of their shiny appearance only with no renowned significant corrosion throughout the twenty-five days of immersion. XRF analysis of the oxides on the corrosion samples of 0.15mm zinc showed decreasing pattern of: Fe2O3 > SiO2.> Na2O >Al2O3 > MnO > CaO respectively. The decreasing order of the percentage of oxides on 2.0mm zinc: Fe2O3 > SiO2 .>Al2O3 > CaO > MnO oxides on 4. 5mm. Aluminium is in decreasing order of; Al2O3 > SiO2.> Fe2O3 > CaO > K2O . On the other side percentage of the oxides of 5.0mm Aluminium is Al2O3 > SiO2 > MnO respectively. Aluminium samples are more durable and resistant which indicates suitability for roofing than zinc sheets.

The effect of anodization and subsequent treatments on corrosion resistance of aluminium

Aluminium samples were chemically prepared by following operations: degreasing, etching I, etching II, and brightening), prior to anodizing in sulfuric acid. Aluminium surface area was 0.2 dm2. The composition of used aluminium samples was determined by the energy dispersive X-ray spectroscopy. Chemically prepared aluminium samples were electrochemically anodized for 45 minutes in a solution of 190 gdm-3 H2SO4 at room temperature, at a current density of 1.7 Adm-2. In the anodizing process, the aluminium sample served as the anode, with lead cathodes. After anodizing, the aluminium samples underwent a colouring process in five pairs of solutions (systems), where each system consisted of two solutions of inorganic salts RxA + RxB (x = 1-5, numbers of solutions). Colouring of the anodized aluminium was carried out at room temperature by immersing the samples in each solution for 7 minutes (e.g., R1A + R1B, τ = 7 min + 7 min). Each used colouring system provides a different colour: green-yellow, brown, light-grey, blue, and orange-gold. After colouring, the samples were treated in a special solution to improve corrosion resistance and silication, resulting in a change in the obtained colour shade. All obtained colours were stable with very nice appearance, allowing such coloured aluminium to be used for decorative purposes. The corrosion resistance of the coloured anodized aluminium samples was investigated by determining the corrosion potential, corrosion current and polarization resistance using potentiodynamic polarization method, as well as by electrochemical impedance spectroscopy. A common feature of all tested samples is a significant improvement in the corrosion resistance of the anodized aluminium after colouring and subsequent treatment in the corrosion resistance improvement solution, particularly after the additional silane treatment.

Evaluation of the Mechanical and Electrical Properties of Multistage Drawn Copper-Clad Aluminum Wire After Annealing Process

This study evaluates the mechanical and electrical properties of copper-clad aluminum (CCA) wire prepared with a total cross-section reduction of 89% through a multistage cold drawing process and subjected to annealing at various temperatures. In addition to the CCA wire, individual samples of oxygen-free copper and aluminum, drawn with a cross-sectional reduction of 50%, were annealed under the same temperature conditions to enable a comparative analysis. Tensile tests for strength and elongation measurements were conducted, while electrical conductivity was assessed through resistivity tests. SEM and EDS analyses were performed to examine the diffusion thickness and the composition of intermetallic compounds generated at the Al/Cu interface of CCA wire. The tensile strength of the CCA wire decreased and its elongation increased up to 250 °C, after which were maintained. As the annealing temperature increased, intermetallic compound layers of Al2Cu, AlCu, and Al4Cu9 were formed at the Al/Cu interface of the CCA wire, and their thickness increased. Electrical conductivity reaches a maximum at 200 °C and then continuously decreases, showing a negative linear correlation with an increase in the diffusion layer thickness of intermetallic compounds. The study confirmed that cold-drawn CCA wire achieves stable mechanical properties and maximum electrical conductivity at the optimal annealing temperature.

Occurrence and characteristics of microplastics in South African beverages

This study presents the first comprehensive assessment of microplastics (MPs) in alcoholic (AB) and non-alcohol (NAB) beverages in South Africa. Beverages in various packaging materials, specifically glass, aluminium, and polyethylene terephthalate (PET) were tested for MP content. The samples were filtered and digested, then stained with Rose Bengal dye to facilitate particle identification, followed by physical and chemical characterisation using stereomicroscopy and micro-Raman spectroscopy, respectively. Fibers were the prevalent shape observed in AB packaged in glass, as well as in NAB (PET), and NAB (Aluminium). The Aluminium samples also exhibited a high abundance of fragments. Multivariate principal component analysis and Pearson correlation coefficient matrix revealed positive correlations between fibers of size ranges 0.02–0.1 mm and 0.1–0.5 mm in NAB samples. While in AB samples, the ranges were observed to be 1–2 mm and 2–3 mm. Six polymers were identified, namely: polypropylene (PP), polyethylene (PE), polyurethane (PU), polyamide (PA), PET, and polybutylene terephthalate (PBT). This study offers a holistic appraisal of MPs in commercially sold beverages in South Africa. It establishes a framework for assessing the socioeconomic impacts of MPs, including their commercial, environmental, social, and sustainability implications.

The NanoSIMS-HR: The Next Generation of High Spatial Resolution Dynamic SIMS.

The high lateral resolution and sensitivity of the NanoSIMS 50 and 50L series of dynamic SIMS instruments have enabled numerous scientific advances over the past 25 years. Here, we report on the NanoSIMS-HR, the first major upgrade to the series, and analytical tests in a suite of sample types, including an aluminum sample containing silicon crystals, microalgae, and plant roots colonized with a symbiotic fungus. Significant improvements have been made in the Cs+ ion source, high voltage (HV) control, stage reproducibility, and other aspects of the instrument that affect performance. The modified design of the NanoSIMS-HR thermal-ionization Cs+ source enables a 5 pA primary ion beam to be focused into a 100 nm spot, a ∼2.5-fold increase compared to Cs+ sources on previous instruments (∼2 pA at 100 nm). The brightness of the new Cs+ source enables an ultimate lateral resolution as high as 30 nm and improved detection limits for a given analysis area. Sample stage movement accuracy is higher than 500 nm, enabling many-fold higher throughput automated analyses. With the new HV control, the primary ion beam impact energy can be reduced from 16 to 2 keV, which enables higher depth resolution during depth profiling (a 2-fold improvement), albeit with a 5-fold decrease in lateral resolution. In the NanoSIMS-HR, the secondary ion column and detection system are identical to those used in the previous series, and the isotopic analysis performance is as precise as in previous NanoSIMS instruments.

Determination of the Rate Change of Electrical Resistance of Aluminium Oxide Film By White Light-Optical Interferometry

A white light, i.e., Fabry-Perot, interferometry was utilized for the first time to determine the rate change of the electrical resistance of aluminum samples during the initial stage of anodization processes in aqueous solution. In fact, because the resistance values in this investigation were obtained by Fabry-Perot interferometry, an electromagnetic method rather than an electronic method, the abrupt rate change of the resistance was called electrical resistance–emission spectroscopy. The anodization process of the aluminum samples was carried out by the DC method in different sulphuric acid concentrations (0.0,2,4,6,8,10% H2SO4) at room temperature. In the meantime, the Fabry-Perot interferometry was used to determine the difference between the electrical resistance of two subsequent values, dR, as a function of the elapsed time of the DC experiment for the aluminum samples in 0.0,2,4,6,8,10% H2SO4 solutions. The Fabry-Perot interferometry was based on a fiber-optic sensor in order to make real time-white light interferometry possible at the aluminum surfaces in the sulphuric acid solutions. The electrical resistance-emission spectra represent a detailed picture of not only the rate change of the electrical resistance throughout the anodization processes but also the spectra represent the rate change of the growth of the oxide films on the aluminum samples in different solutions. As a result, a new spectrometer was developed based on the combination of the Fabry-Perot, i.e., white light, interferometry and DC method for studying in situ the electrochemical behavior of metals in aqueous solutions. In addition, the obtained values of the resistance of the combination of the Fabry-Perot interferometry and DC method were compared with resistance values of the aluminum samples in 0.0,2,4,6,8,10% H2SO4 solutions by the electrochemical impedance spectroscopy (EIS). Keywords: Fabry-Perot interferometry, White light interferometry, Electrical resistance, Anodization, Fiber-optics sensor, DC method & EIS. Figure 1

New application of a calorimetric sensor: Measurement of the heat capacity of heat-conducting small parts

This study explores a novel application of a calorimetric sensor to measure the heat capacity of small heat-conducting parts under varying environmental conditions. The sensor, a hybrid of a heat conduction calorimeter and a differential scanning calorimeter (DSC), has been adapted from its original use on living skin to measure conductive materials. We present a detailed description of the sensor's instrumentation, its operating model, and the experimental procedure. The sensor's accuracy is evaluated through experimental measurements on aluminum and brass samples, showing a maximum deviation of 5 % and a mean deviation of 2.35 % from the theoretical values. Additionally, finite element method (FEM) simulations are employed to further investigate the sensor's performance, confirming that both measurement time and sample size significantly influence the results. This research demonstrates the potential of this calorimetric sensor for rapid and accurate thermal analysis of small heat conducting parts, with potential applications in various scientific and industrial fields.

Synthesis of poly aluminium chloride (PAC) from aluminum cable waste through the polymerization process

Cable waste is classified as inorganic waste that is difficult to decompose. Aluminum cable waste has good coagulant properties if it can be synthesized into Poly Aluminium Chloride (PAC) because the active aluminate groups can aggregate suspended materials in water into flocks during the coagulation-flocculation process in water purification. PAC is made by hydrolyzing aluminum samples with a 33% HCl solution. The sample is then left for one day to complete the hydrolysis process. After the formation of the AlCl3 solution, polymerization is carried out by adding a Na2CO3 solution. In the research conducted, the best result was a turbidity reduction value of up to 2.96 NTU with the addition of 30 ml of AlCl3 monomer and a Na2CO3 initiator with a concentration of 7N. After optimization using Response Surface Methodology (RSM) in the Design Expert 13 software, the most optimal result for the synthesized PAC was found to reduce wastewater turbidity to 2.609 NTU with variables of 25.992 ml of AlCl3 monomer volume and 5.248N of Na2CO3 initiator concentration. Based on this research, the concentration of the initiator has a significant effect on the ability of the monomer to bind into a PAC polimer chain.

Parameter dependence of depth and lateral resolution of transmission Kikuchi diffraction

The spatial resolution of transmission Kikuchi diffraction (TKD) depends on experimental parameters such as atomic number, accelerating voltage, sample backtilt and thickness. In this work, the dependence of spatial resolution on these parameters is explored by using bilayered coarse-grained/nanocrystalline samples to determine the depth resolution. Digital image correlation of the Kikuchi patterns across grain boundaries is used to measure the lateral resolution. The depth resolutions of TKD in aluminium, copper and platinum at 30 kV for an untilted sample were 80, 32 and 14 nm respectively. These worsened with increasing sample backtilt and slightly improved with decreasing accelerating voltage. The best physical lateral resolution obtained was 6 nm, at 30 keV in a 41 nm thick aluminium sample with no backtilt. The lateral resolution worsened with increasing sample thickness and backtilt, contrasting with some previous reports. Accelerating voltage and atomic number did not have a significant impact on the measured lateral resolution within the scatter in the data.

Thermal Conductivity Measurement System for Functional and Structural Products

An automated system for measuring the thermal conductivity of functional and structural materials was developed. The main building blocks of the setup are the following: heating unit and cooling unit creating a heat flux gradient in the test sample; thermal resistances for temperature registration and control; and thermal pads for better contact between parts of the setup and the sample. The effect of the thermal conductivity of thermal pads and thermal resistances on the distribution of thermal fields in the developed setup was studied by computer modelling. A control software for the measuring setup was developed based on the hardware implementation of the steady-state Fourier’s law-based method for the determination of thermal conductivity. The stopping criterion for the setup control software is the equality of heat fluxes in the heating and cooling units, as well as the stability of the thermal conductivity coefficient readings. The testing and calibration of the device were carried out using a sample of pure aluminum (99.999 wt.% Al). It was found that the experimental value of the thermal conductivity coefficient of the aluminum sample at room temperature (T = 22 °C) is <λ> = 243 ± 3 W/m·K. This value of the thermal conductivity coefficient is consistent with the literature data and experimental values obtained by the laser flash method, which ranges within λ = 210–260 W/m·K.

Experimental Analysis of Cavitation Erosion: Parameter Sensitivity and Testing Protocols

The scientific goal of this study was to investigate the effects of various parameters on cavitation-induced erosion, with the aim to enhance the understanding and assessment of cavitation resistance in hydraulic systems. Cavitation erosion poses significant challenges to the durability and efficiency of hydraulic components, such as those found in hydropower plants and pumping stations. Prompted by the need to improve the reliability of cavitation testing and material assessment, this research conducted a comprehensive sensitivity analysis of a cavitation jet apparatus (CJA). This study employed an experimental platform that consisted of a vertical cylindrical test tank, a submerged nozzle, and an aluminum sample. By examining a range of orifice diameters, this research identified that smaller diameters led to increased erosion intensity, with the most pronounced effects observed at a diameter of 2 mm. Furthermore, various standoff distances (SoDs) were tested, which revealed that shorter distances resulted in greater erosion, with the highest impact noted at an SoD of 5 cm. This study also evaluated different nozzle geometries, where it was found that a 132° conical sharped edges nozzle, combined with an orifice diameter of 2 mm and an SoD of 5 cm, produced the most severe erosion. Conversely, chamfered edges nozzles and a commercial nozzle (MEG2510) with an SoD of 10 cm or greater showed reduced erosion. These results highlight that by standardizing the testing duration to 1200 s, the CJA could reliably assess the cavitation resistance of materials. This study established a clear relationship between increased pressure and higher impact forces, which led to more severe erosion. The findings underscore the effectiveness of the CJA in evaluating material resistance under various cavitation conditions, thus addressing a critical need for reliable cavitation testing tools.

Nanoparticle integration in adhesive and hybrid single lap joints: effect on strength and fatigue life under environmental aging

Examining the mechanical performance of CFRP and aluminum samples subjected to environmental aging is crucial. Additionally, it is essential to develop methods to enhance their mechanical properties. This research investigates the impact of fullerene and single-walled carbon nanotubes (SWCNT) on the fatigue life and static strength of bonded and bonded/bolted joints. The study focuses on composite-to-composite (CTC) and composite-to-aluminum (CTA) substrates under three-point bending, both before and after hygrothermal aging. The samples were divided into four categories: (1) neat specimens, (2) specimens with added fullerene, (3) specimens with added SWCNT, and (4) specimens with a combination of 50% SWCNT and 50% fullerene. The experimental results indicated that the optimal nanoparticle ratio for bonded joints differs from that for bonded/bolted joints. Adding nanoparticles to the adhesive increased the fatigue life of SLJs, particularly in samples containing mixed particles and SWCNT. In some cases, nanoparticles amplified the effect of hygrothermal conditions, enhancing fatigue life further. The integration of nanoparticles into the adhesive and the use of bonded/bolted joints significantly improved joint strength, with the combination of both techniques yielding the best results. These modified joints offer a promising alternative to traditional joints in terms of strength and fatigue life. The study enhances understanding of the aging of adhesive and hybrid joints, especially dissimilar joints (composite to metal), and provides insights into their behavior under various environmental aging conditions. These methods show potential for optimizing joints and composite structures, improving durability, and reducing the likelihood of operational failures.

Evaluation of tribological parameters for boron carbide and graphite infused aluminium hybrid composite fabricated by stir casting technique

The present work focuses on suggesting Gr as a valuable self-lubricating reinforcement for hybrid composite samples and offering a minimum wear rate for sliding pairs with fewer mechanical surface defects at the same time. A series of samples were fabricated using the route by stir casting method considering B4C and Gr as the two reinforcements. The morphology of the sample has been studied using the X-ray diffraction graphs, Energy dispersive X-ray analysis and Scanning electron imaging stating the homogeneity of reinforcement in various composite cast. The theoretical and experimental density of the series of samples has been studied and compared stating the low porosity of the samples fabricated. A maximum wear rate (Wr) of 0.351 × 10−4 mm3/m. was found for pure aluminium sample against EN31 steel disc with 0.053 as friction coefficient (µ). Wr was somehow seen to reduce up to 0.286 × 10−4 mm3/m for Al-B4C composite with µ of 0.48. For hybrid samples, the wear rate was further seen to improve to 0.187 × 10−4 mm3/m for Al-B4C and Gr 2.0% weight with µ of 0.38. Least Wr was found for composite having Gr 3.5% weight, of 0.149 × 10−4 mm3/m. with µ of 0.36. SEM images of the worn surface give evident results for delamination and crack formation on the pin face for the pure-Al sample. Taguchi-ANOVA analysis has been carried out showing the valid contribution of pin type, load and sliding speed on Wr and friction coefficient as the P-value lies below 0.05 for input parameters considering the 95% confidence level of the model developed. An F-value of 44.57 with R2 of 0.895 is developed for Wr model and an F-value of 54.2 with R2 of 0.934 for the µ model.

PVD Coatings for Lightweight Bipolar Plates

Bipolar plates are one of the main components of proton exchange membrane fuel cells (PEMFCs). Their functions include distributing reactants, supporting the cell, and conducting heat and electricity. They account for a significant proportion of the fuel cell stack’s weight and volume. The main materials currently used for bipolar plates are graphite and stainless steel. Aluminium has a much lower density than steel and is easier to form than both steel and graphite. Its use, therefore, would allow fuel cells with higher power densities but is hindered due to it being prone to corrosion. This work focused on the development of corrosion-resistant and conductive coatings to address this issue. Carbon coatings with Ti and Cr adhesion layers were deposited on aluminium substrates using closed-field unbalanced magnetron sputtering. These coatings were tested for corrosion properties and performance on the cathode side of a single-cell fuel cell. Coated aluminium samples were also tested for their ability to maintain their corrosion protection after being formed. Coating with a Cr adhesion layer outperformed that with a Ti adhesion layer in both forming and fuel cell tests, demonstrating much lower performance degradation after accelerated stress testing.

Optimization of the interfacial properties between mechanically and electrochemically treated aluminium and nano-modified coatings for printed outdoor applications

The aim of this research was to analyze the interfacial properties between the surfaces of mechanically and electrochemically treated aluminium substrates and the printed coatings modified by the addition of silicon dioxide (SiO2) and titanium dioxide (TiO2) nanoparticles. The nanoparticles were added to the printing inks in various concentrations with the scope to optimize the interface properties of the prints for outdoor applications. The surface, as well as the structural and mechanical properties of the printed coatings were evaluated. Various methods were employed to measure and analyze the surface and interfacial properties of aluminium and coatings. Surface microphotographs and the roughness of the treated aluminium substrates were examined, the surface free energy of the aluminium and the coatings as well as the adhesion properties were calculated, and the thickness and optical density of the coatings were measured. Considering that the treated aluminium samples prepared for this research had quite textured and different surfaces, the contact angles used for the calculation of surface free energy were calculated with and without Wenzel model to obtain detailed information about the interactions between the surface of aluminium samples and the printed modified coatings. The results showed that the type of treatment of aluminium substrates as well as the modification of the printing inks have a significant influence on the adhesion and surface properties of the coatings considered. Furthermore, the results demonstrated that the produced nano-modified coatings can be used as printed coatings or as customized primers for applying various types of inks and coatings.

Measurement of thickness and ultrasonic velocities based on imaging method using laser-generated ultrasonic waves at thermoelastic regime

Abstract This study introduces a simple method for determining thickness and ultrasonic velocities, including skimming longitudinal waves, longitudinal waves, and shear waves, utilizing laser-induced ultrasonic waves at the thermoelastic regime and the time-position imaging technique. Laser scanning was performed on two aluminum samples with thicknesses of 6 mm and 10 mm, generating data on the arrival time of multiple wave modes according to the separated distances of two laser spots. Using the least squares technique, the data obtained from the experiment were employed to fit theoretical curves of various waves, enabling the simultaneous determination of several material parameters. The proposed method exhibits high accuracy in determining thickness, with a maximum relative error of 1% for thicknesses up to 10 mm. Additionally, comparisons with theoretical calculations reveal maximum errors of 1 % for shear wave velocity and 0.8 % for longitudinal wave velocity. The ratio between the velocity of skimming longitudinal wave and bulk longitudinal wave of 0.95 was established, providing a prospective method to calculate longitudinal wave velocity through guided waves along the surface.

Exploring the machining characteristics of aluminum 6061 using nanosecond pulse fiber laser machine

The present study aims to probe the influence of nanosecond laser parameters on the surface quality of aluminum material (Al 6061) using a full factorial design approach. Additionally, the study utilizes the Harris Hawks optimization (HHO) algorithm to determine the optimized laser parameters for achieving desirable surface features on straight-cut aluminum samples. Subsequently, the machined samples are analyzed through optical microscopy, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The evaluation criteria for the present study are taper, surface roughness, and heat-affected zone (HAZ) thickness. The results revealed that average laser power significantly impacted the taper (17.01%), and scanning speed contributed significantly to the taper (26.62%). The average power and scanning speed combined showed the most substantial influence on taper (47.76%). Furthermore, the average power had the most significant effect on the heat-affected zone (77.76%) and surface roughness (SR) (72.22%). The optimal conditions determined by the HHO were a pulse frequency of 100 Hz, a scanning speed of 10 mm/s, and an average power of 40 W, resulting in heat-affected zone = 36.047, surface roughness = 5.496, and taper angle = 23.188. These findings hold significant implications for enhancing the surface characteristics of aluminum in laser machining processes, thereby benefiting industries such as aerospace, automotive, and electronics.