Surface Review and Letters

Primary manufacturing processes like casting, forming, and shaping (forging, rolling, drawing, extrusion, sheet forming, and molding) further need any of the secondary manufacturing processes like turning, drilling, boring, planing, milling, grinding, etc. In order to produce superior quality products, and to enhance productivity, the selection of desirable process parameters is significant. The selection of suitable process parameters is essential for accomplishing the desired component. Based on the existing literature, this study examines the causes, effects, and variances regarding chip formation, tool geometry, thrust force, torque, surface roughness, drilling time, and other drilling quality characteristics in the most typical machining operations such as drilling. Developing a repository on these process parameters will guide the process planning engineer for ready reckon. Therefore, this work aims at the development of a detailed repository with the study of characteristics. Further, this literature review comprehends the characteristics of a behavior with its reasoning, which was detailed in the past decade. It reveals the beneficial process parameters for achieving better production rate and superior quality.

Nanomaterials can be employed in various medicinal industries because of their unique characteristics versus bulk materials. Nanosized particles of Titanium dioxide were fabricated using the laser irradiation technique in this work. After production, the physical properties of Titanium dioxide were identified by Ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared (FTIR) spectrum, X-ray diffraction, FTIR, and Transmission electron microscopy (TEM) techniques. Regarding TEM micrographs with various laser energies, the nanoparticles exhibit a spherical appearance, with average diameters ranging from 19nm to 26 nm based on the laser energy. X-ray diffraction results from combined Anatase and Rutile crystal structures in the prepared nanoparticles to indicate the production of Titanium dioxide nanoparticles. The FTIR analysis showed that the O-Ti-O mode includes a peak at approximately 480–550cm${}^{-1}$. In this study, the antibacterial efficacy of Titanium dioxide nanoparticles was investigated against Staphylococcus aureus and Escherichia coli, as well as anticancer assay against prostate cancer cell line (PC-3 cells). The result shows that the effectiveness of prepared nanoparticles against S. aureus is more significant than that in E. coli, and the findings indicate the ability of prepared nanoparticles as an antiproliferative agent against PC-3 cells. In conclusion, the prepared nanoparticles could be used as a future strategy for further biomedical applications.

In this work, palladium nanoparticles (Pd NPs) are synthesized by laser ablation in liquid (PLAL) with wavelength 532nm (second harmonic Nd:YAG laser) at different laser energies 360, 660, and 800mJ with 200 pulses and an electric coil is used to generate a magnetic field. The resulting nanosolution was deposited on the previously prepared PS. The morphological and structural properties of the prepared substrates (Pd NPs/PS) are calculated by X-ray diffraction (XRD) pattern, Atomic Force Microscope (AFM), and Transmission Electron Microscopy (TEM). Their results showed that with the increase in the energy of laser pulse, the average particle size was 30.73, 22.60, and 18.01nm. Optical properties of Photoluminescence (PL) spectra show decrease of energy band gap at 2.38, 2.43, and 2.47eV with an increase in the energy. The sensitivity of application samples Pd NPs/PS/Si gas sensors for NO₂ and H₂S gas was also investigated with respect to temperature variations. Pd NPs/PS/Si gas sensors have a maximum sensitivity of NO₂ gas around 52.6% at $25^{\circ }$C for sample prepared at energy 360mJ but the highest sensitivity of H₂S gas was 31.2% at $25^{\circ }$C for energy of 660mJ. The effects of the operating temperature on reaction and recovery durations for various laser ablation energies are also discussed.

Surface characteristics of dissimilar metal joints interface play a crucial role on its functional performance. In this study, the microstructural, metallurgical and corrosion behavior of the microwave processed and TIG welded bimetallic joints interface surfaces were investigated. Metallurgical and mechanical properties of the joints interface surfaces were studied using SEM/EDS, XRD and microhardness techniques. The hot corrosion behavior study of both joints was carried out at elevated temperature in actual environment of biomass fuel-fired boiler as well as in simulated boiler environment. The after-corrosion behavior of both joints was analyzed using SEM and XRD methods. TIG-welded samples exhibited more loss in weight during both actual and simulated corrosion environments. The depletion of chromium from substrates in the actual corrosion environment proved that chromium is involved in controlling corrosion rates by forming the protective oxides during corrosion cycles.

Inconel alloy has been a solution to diverse fields where automobile industry, aircraft, nuclear reactor are the foremost and major applicants of Inconel alloy. But the aim is precise manufacturing in minimum time. Inconel is known for its hard to machine characteristic. This paper illustrates the machining effect on Inconel 601 in EDM. Electrode discharge machining with its ability to machine hard conductive metals is the most recognized and suitable nonconventional machine for the purpose. Experiments with four level of variation and five parameters, (that is, OCV, peak current, pulse on time, duty factor and flushing pressure) have been conducted in 16 different combinations under L16 orthogonal array. Metal removal rate (MRR), surface roughness ($R_a$), surface crack density (SCD), and white layer thickness (WLT) have been calculated herein. Surface roughness has been depicted with the help of Taylor Hobson materialize finishing tester. The view of the fact that conventional Taguchi technique cannot be used to solve the multiple response optimization problem independently, so TOPSIS method has been used in this paper to convert multiple responses into an aggregated performance index (called closeness coefficient $C_i^{+}$) which has been optimized finally by the Taguchi technique. In this, MRR and Ra have been optimized by using the TOPSIS technique and it is found that by using optimal setting i.e. A₄B₁C₂D₁E${}_{2,}$ MRR will be higher while Ra will be lower. Moreover, micro-graphical studies have been conducted to analyze various surface irregularities (SCD and WLT) of EDMed Inconel 601. SCD and WLT have been investigated with respect to optimal settings (A₄B₁C₂D₁E₂) and obituary settings run no. 10 (A₃B₂C₄D₃E₁) and better results have been obtained in optimal settings as compared to obituary settings.

The corrosion behavior of 316 stainless steel with 10wt.% B₄C composites has been investigated using electrochemical measurements and electron backscattered diffraction (EBSD) and scanning electron microscopy (SEM) analyzes are performed. Spark plasma sintering (SPS) is used to achieve various heat treatments, which are performed at the temperatures of 800^∘C, 900^∘C, and 1000^∘C. It significantly affects the materials’ ability to resist corrosion. The increase in grain size improves corrosion resistance, except at 900^∘C when recrystallization is imperfect. However, grain homogeneity should be taken into consideration. The corrosion behavior of the composites is assessed using Tafel plots. The corrosion rate of the sample at 900^∘C (0.2945mm/yr) is significantly lower than the rates of the samples at 800^∘C and 1000^∘C, respectively, as per the corrosion process of composites of 3.5wt.% NaCl solution. The B₄C contents have a significant impact on the particle size reduction, low-density average crystallite size, mechanical, hardness, corrosion resistance, and thermal stability of composite powder. It is primarily utilized in nuclear applications as a neutron radiation absorbent. The research has revealed that the sample at 900^∘C has fewer grain boundaries and the finest passivation film quality and superior corrosion resistance are found in intermediate grain size.

By the use of the Migdal–Kadanoff renormalization group technique and the mean field approximation, we have explored the critical behavior of the semi-infinite mixed spin-7/2 and spin-1/2 Blume–Capel model. As a function of the computation ratios (bulk-surface) R and Y, different phase diagrams in the bulk and on the surface are classified and determined in the (surface anisotropy, temperature) plane. We have found four types of phase diagrams characterized by ordinary, extraordinary, surface, and special phase transitions. The derivative of the free energy and the behavior of the bulk and surface magnetizations are plotted at very low temperatures proving the existence of first-order transitions for both the surface and bulk. We have also presented the related fixed points and the critical exponents manifesting several classes of universality at the surface. Otherwise, a comparison was made between the two methods as well as with previous studies.

Different types of superhydrophobic materials have been fabricated by constructing surfaces with low surface energy and micro-nanostructures, most of which are coatings. Due to the fragile rough structure of the coating, it is very easy to lose its superhydrophobic properties when exposed to friction, corrosion, high temperature, and other effects of the external environment. This has largely hindered the large-scale application of superhydrophobic materials. Here, a rigid superhydrophobic material with polyurethane foam as the substrate, polytetrafluoroethylene (PTFE) nanoparticles as the matrix phase, and carbon nanotubes as the reinforcing phase have been reported. The fabricated material showed excellent superhydrophobicity (157^∘ ± 1^∘) and robustness. The contact angle of the superhydrophobic material surface remained above 150^∘ and the rolling angle below 10^∘ after 1000 cycles (distance is 40m) of abrasion using 800 # sandpaper at pressure of 5kPa.