An embedded system-based spin coating machine has been developed to grow thin films. Pure zinc oxide (ZnO) and magnesium-doped zinc oxide (ZnO: Mg) thin films with different doped samples have been prepared using the spin coating technique for LPG gas sensing application. The spin coating machine is fully controlled by a PIC microcontroller (PIC16f877A), which can drive a driver circuit to drive a spinning motor, and ZnO: Mg thin films are deposited using this machine. XRD results indicated that the movie has a hexagonal wurtzite structure with a preferred orientation, and the crystallite size increases with the increasing doping concentration of Mg. The surface morphology investigation shows that grains are irregular in shape, and doping concentrations do not influence the surface morphology. From the TEM image, particle sizes observed ranged between 23 and 28 nm, with an average value of ~25.8 nm. The maximum visible average transmittance was 96% for an optimum Mg doping concentration of 10 wt% %. The investigated DC electrical conductivity of Mg-doped ZnO thin films shows enhanced electrical conductivity compared to pure ZnO, and the AC conductivity is decreased with increasing Mg doping concentrations from 5 to 10 wt%. The operation and sensing mechanism of Pure ZnO and ZnO: Mg thin films behind their impressive results has been studied in depth.

Pantograph slide materials demand excellent mechanical and electrical properties for rail applications. Carbon-copper (C-Cu) composites combine the high electrical conductivity of copper with lightweight and wear-resistant traits of carbon. Using palm kernel shells (PKS), a palm oil industry by-product, promotes sustainability but presents challenges in achieving uniform distribution and performance retention. This study examined PKS and graphite as carbon sources in C-Cu composites enhanced with carbon nanotubes (CNT), focusing on optimising mechanical and electrical properties for pantograph slides. However, CNT is known for its difficulty in achieving optimum dispersion in composites, as strong van der Waals forces cause aggregation, uneven distribution, and porosity, thereby reducing the electrical and mechanical properties. Balancing carbon content, CNT reinforcement, copper, and resin matrix is crucial to prevent conductivity loss and structural weaknesses. Varied CNT content (1wt% to 5wt%) was analysed for its impact on hardness, transverse rupture strength (TRS), and electrical resistivity of the C-Cu composite. Fabrication involved material mixing, cold pressing, warm compaction (150°C, 490 kN, 5 minutes), and post-baking process (250°C, 4 hours). The 2 wt% CNT sample achieved superior results, including 102.5 HRR hardness, 37.63 MPa TRS, and 32 µΩ.m resistivity before post-baking, due to excellent CNT dispersion. Post-baking enhanced bonding and mechanical properties but raised resistivity by altering conductive pathways. Poor dispersion of CNT at contents more than 3 wt% led to agglomeration and inferior properties. The findings highlight the critical role of CNT dispersion and the post-baking process in achieving optimal composite performance to maximise CNT potential. These results are comparable to commercial pantograph slides, contributing to the development of high-performance materials for rail applications.

In the cosmetics packaging industry, UV coating is applied to enhance surface characteristics by providing scratch resistance, a glossy finish, stain resistance, and improved durability against environmental exposure. UV coating is a curing process that utilizes ultraviolet (UV) lamp radiation. This process is influenced by several parameters, including conveyor speed, UV lamp temperature, and the distance between the UV lamp and the product. However, in the current packaging process, these parameters are often set based on routine practices rather than standardized guidelines. As a result, improper UV curing can lead to cracking defects that appear after the product assembly stage. These cracks are caused by suboptimal UV exposure during the curing process, which compromises the mechanical integrity of the product. This paper intends to determine the appropriate standard temperature settings based on a comparative analysis of UV lamp temperatures and distances. Experiments were conducted using four UV lamps with temperature settings of 50°C, 75°C, and 100°C, repeated across five trials. The results show improved mechanical properties and a significant reduction in cracking defects. Furthermore, the findings support the development of more efficient and standardized settings for the UV curing process.

In virtual process chains for discontinuous fiber-reinforced polymers, clustering of fiber orientation tensors reduces the number of macroscopic material cards required for downstream structural and warpage simulations. However, it remains unclear whether including the additional information provided by the fourth-order fiber orientation tensor improves clustering quality. This study investigates the influence of second-order vs. fourth-order informed clustering on clustering outcomes and the resulting orientation-averaged mechanical properties. Using parameterizations based on harmonic decomposition, rotation-invariant clustering is performed in both the second-order and fourth-order parameter spaces. Results from injection molding simulation data indicate that the level of tensorial information has limited effect when the fourth-order tensor is computed via a closure approximation, as the deviatoric parameters are nonlinearly dependent on the second-order parameters. In contrast, the choice of clustering algorithm -- KMeans vs. Birch -- has a more pronounced influence on cluster shapes and allocations. Furthermore, we demonstrate that clustering affects orientation-averaged stiffness properties, with deviations most pronounced near cluster boundaries and rarely occurring tensor shapes.

Incomplete impregnation is a remaining challenge in the production of thermoplastic unidirectional (UD) tapes, particularly for the melt impregnation. This study investigates an approach analogous to multi-stage die impregnation by re-calendaring partially impregnated UD thermoplastic tapes, where different closing forces under controlled processing conditions are used to enhance impregnation quality. In this work, polypropylene–carbon fiber (PP-CF) tapes with a width of 20 mm and a thickness of 400 µm were produced by using an Xplore UD Tape Line with a closed pultrusion die. As a model sample, these tapes were deliberately produced under conditions expected to result in partial impregnation by setting the die pressure and pultrusion rate accordingly. To improve impregnation, the tapes were subsequently subjected to calendaring with different nip force passes in a different line, thereby mimicking a staged or multi-die consolidation approach. Results show that calendaring induces pronounced geometric reconfiguration accompanied by improved impregnation quality. Tape thickness was reduced by up to approximately 65%, while tape width increased by up to approximately 70%, indicating effective lateral spreading under compressive and shear stresses. Optical microscopy of polished cross-sections revealed a reduction of dry fibre regions and improved resin continuity within inter-filament gaps at intermediate calendaring nip force. Density-based fiber volume fraction of the tape measurements showed only a slight increase in the range of 2–3%, suggesting that consolidation was governed primarily by fibre rearrangement and spreading rather than significant resin squeeze-out. The findings provide practical insights into how the calendaring unit of a thermoplastic tape manufacturing line can be adapted for multi-stage consolidation, offering improved impregnation quality in thicker thermoplastic tapes that are more prone to impregnation defects. This approach may also serve as a bridge solution when the pressure build-up is limited.

This study investigates the compaction behavior of woven flax rovings, a crucial aspect of the preforming stage in composite manufacturing. It focuses specifically on the challenges posed by their inherent heterogeneity and structural variability. Although the durability of flax-based composites is widely recognized, accurate numerical modeling of their processing, particularly for liquid composite molding (LCM), remains limited by the lack of detailed experimental data on roving mechanical behavior, including data capturing the inherent variability of the material. This research used a combined experimental approach, comprising computational microscopy for microscale deformation analysis and macroscopic compression tests, to characterize the mechanical response of flax rovings under compaction. Results highlight the need to develop sophisticated simulation frameworks that account for statistical variations in material properties but also the specificities of the flax roving response, which differs considerably from that of synthetic fibers rovings. The experimental dataset generated provides a valuable basis for identifying material parameters and validating advanced simulation frameworks aimed at improving performance predictions of manufactured components.

This paper presents a metallographic and fractographic study of AISI 304 austenitic stainless steel subjected to mechanical loading in the sensitized condition. Static three-point bending tests and impact tests were carried out to evaluate how sensitization affects the mechanical response and fracture behaviour of AISI 304. The study compares the initial state of the material with its condition after sensitization at 700 °C for 10 h, with emphasis on changes in plastic deformation and fracture mechanisms. Microstructural evaluation was performed using light microscopy, while Vickers microhardness measurements provided insight into local mechanical changes. Fractographic analysis using scanning electron microscopy revealed differences in fracture surface morphology. Results demonstrate a decrease in microhardness, reduced impact energy, and noticeable differences in fracture morphology following the sensitization treatment, indicating that the heat treatment influences both the mechanical response and failure behaviour of AISI 304.

This study aimed to present a method for measuring the mechanical strength and electrical chargeretention properties of fibers containing nano-sized oxide particles, which have become widely usedin recent years, and to clarify the fundamental physical properties of these fibers. There have beenfew studies measuring the mechanical and electrical properties of composite fibers containing nanosizedoxide particles. Polyester fibers containing SiO2 and ZrO2 nanoparticles were fabricated usingindustrial techniques to clarify the effect of particle introduction on strength. Furthermore, theelectrostatic charge properties of fibers containing these particles, which act as insulators, weremeasured, revealing that mechanical strength and electrical charge retention properties are mutuallyexclusive parameters. Increasing the nanoparticle content decreased mechanical strength, butprolonged the charge half-life and improved electrostatic retention. Furthermore, it was shown thatthis phenomenon can be represented using an equivalent circuit model of a resistor and a capacitor.

In the paper the detailed structural changes in the cutting zone were determined using metallography. Accurate determination of parameters such as shear angle, slip angle, chip thickness, cutting ratio, chip separation point, etc. required metallographic analysis on a relatively complex sampling of the cutting area. We performed the analysis on an orthogonal cutting. We achieved orthogonal cutting by turning a thin-walled Inconel 718 and C45 alloy tubes and setting the lath bit cutting edge perpendicular to the tube axis. In real state, the shapes in the cutting zone are more complicated therefore the chip thickness was determined using quantitative metallography from the equality of areas and the resulting point of transition between the chip and the machined surface. The shear angle starts from this point and is a tangent to the cutting edge, the direction of which was determined using the Thales circle. The distance between this point and the machined surface which represents a layer which is not separated from the machined material but is planar deformed was determined too. The depth of the deformed layer and the value of deformation on the machined surface was determined by quantitative metallography. A much simpler numerical simulation was performed with the same parameters using Deform 2D/3D software package. Numerical simulation could not fully replace metallographic analysis, but to some extent numerical simulation can be used instead of metallographic analysis.