Material Design & Processing Communications最新文献

The literature on using ceramic particles from agroindustrial wastes to enhance the engineering performance of metallic materials is limited. This study explores using rice husk (RH) and white clay (WC) particulates to develop zinc-based composite coatings on A36 steel. Four cathode specimens (80 × 40 × 2 mm) of A36 steel and two zinc anodes (50 × 30 × 2 mm) were prepared. The steel specimens were coated with Zn-10RHWC(t25), Zn-10RHWC(t30), Zn-15RHWC(t25), and Zn-15RHWC(t30), denoted as S1, S2, S3, and S4, respectively. The concentrations used were 10/15 g/L, with deposition times of 25/30 min at a constant cell voltage of 0.5 V. Corrosion rates (CRs) in 3.5 wt.% NaCl were investigated according to ASTM and NACE standards. The coated samples’ hardness, tensile strength (TS), and wear rate (WR) properties were also examined. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to study the morphology and crystallization of the coatings. The coated specimens exhibited significantly lower CR than the uncoated steel (CR = 8.45 ± 0.58 mm/year). CR values for S1 to S4 were 5.74 ± 0.41, 2.18 ± 0.42, 3.09 ± 0.38, and 5.92 ± 0.45 mm/year, respectively. All coated specimens showed substantial improvements in TS over the uncoated specimen (4.81%, 2.83%, and 4.29% for upper, middle, and lower sections, respectively). Regarding deformation modulus, the Zn-15RHWC(t25) samples exhibited improvements of about 1.31% and 1.38% in the upper and middle sections, respectively, while the lower section experienced a decrease of 2.03%. The study demonstrates significant enhancements in the engineering properties of A36 steel coated with Zn-13, RH, and WC using the dual-anode electrolytic codeposition technique.

This investigation has led to a new femur hybrid metaimplant with enhanced properties. It consists of honeycomb and auxetic cells with a tuned material ratio along the femur stem. In the design of the metaimplant, we focused on creating the desired lateral expansion, which makes it a good candidate as the personalized femur implant, decreasing the chance of bone–implant interface failure. For this aim, analytical and computational homogenization methods are used to evaluate a hybrid metamaterial under off-axial compression loading. We show that the lateral expansions of the metamaterial are widely tunable by tailoring Young’s modulus, Poisson’s ratio, and the material ratio of the constituent materials. The hybrid metamaterial outperformed all-auxetic and all-honeycomb designs in terms of bilateral expansion, and the one with maximum lateral expansion was selected for implementation in the design of the metaimplants. The resulting metaimplants show compression on either side of the implant and give smoother stress distribution and lower stress concentration at the contact region of the implants with the femur bone surfaces in comparison to the solid and porous femur implants.

This study explores the potential of parring bamboo fiber (PaBFeR) as a composite reinforcement material with flame retardant polyester (FR-P). This study addresses the wettability of PaBFeR by measuring the contact angle of FR-P resin on the surface of PaBFeR uses the sessile drop method in accordance with ASTM D7334-08 (2022), as many as seven drops per sample. The alkaline treatment at 85°C for the delignification of PaBFeR varied by 3%, 5%, and 7% and the washing varied for 45, 90, and 135 min to see the effect on the value of the formed contact angle. The results obtained are that the optimal wettability for application in FR-P matrix PaBFeR-reinforced composites is NaOH11%90 with a contact angle range value of 42^° ≤ θ ≤ 48^° and average contact angle 44.86^° ± 1.88^°. In contrast, the NaOH3%45 sample was declared the least optimal configuration because it had an average contact angle value of 33.57^° ± 7.44^° and a very wide range of contact angles (21^° ≤ θ ≤ 46^°), indicating the instability of the results.

The flow behavior and precompaction resistance were investigated for the first time as part of this study. New laboratory methods were developed and applied for this purpose, some of which were based on already established methods. In order to evaluate the influence of temperature on the paving behavior of the asphalt paver, the flow behavior and precompaction resistance were investigated for three selected asphalt mixes (AC 11 DS, SMA 11 DS, AC 16 BS). The temperature was varied in three steps (130°C, 160°C, and 190°C). An extensive literature review of possible laboratory tests was conducted, which concluded that static compaction and the funnel fall test are suitable for investigating the corresponding properties of the asphalt mixes. The results showed that the bulk density of a loose fill asphalt mix is significantly dependent on temperature. Higher temperatures result in higher poured density due to the thermoviscosity of the bitumen, specifically, the viscous τ_visc and cohesive τ_c resistance components. Considering the performed laboratory tests, this phenomenon results in the loose fill of all tested asphalt mixes having a lower precompaction resistance at lower temperatures. In addition, the influence of temperature on the flow behavior and thus the internal friction of the asphalt mixes was demonstrated. Higher test temperatures resulted in a substantial reduction in flow time up to 225% and thus significantly improved flow behavior.

The fracture propagation on the rock causes failure and impacts the sustainability time of the structure. As part of the present work, sandstone with the variation of preexisting crack angle was simulated using the extended finite element method (XFEM). The crack propagation on sandstone has a preexisting fracture angle of 30°, 45°, and 60°, with an equivalent crack length. The impact of preexisting fracture angle on the possibility of crack propagation, failure mechanism, and displacement at a critical point of all models was studied. The numerical simulation revealed the crack angle of the model control vibration and its impact on the model’s seismic stability. The XFEM results are validated with reference to those available in the literature. Artificial neural networks (ANNs) are used for prediction by considering the training, testing, and validation process and analyzing prediction errors. The present simulation’s conclusion significantly supports the model’s displacement prediction with no crack propagation occurrence. In addition, by considering the preexisting fracture angle of a model, the load sustainability can be estimated.

In this study, the microstructure and defects of an Al-Mn-Mg-Zr alloy produced by the Powder Bed Fusion–Laser Beam (PBF-LB) technology are investigated. The influence of the process parameters on the microstructure and defects is demonstrated. Aluminum alloys are usually prone to cracking during solidification. However, finding the optimal parameters of the PBF-LB process yielded three-dimensional specimens of Al-Mn-Mg-Zr alloy with densities reaching 99.6% of the theoretical value, free from cracks. It is shown that manganese not only precipitates as a brittle Al₆Mn intermetallic compound after solidification but also forms a supersaturated solid solution of manganese in aluminum. The influence of the process parameters on the surface roughness of the manufactured samples and their microhardness was evaluated. It is also shown that the cooling rate of the melt pool has an effect on the microstructure of the samples obtained at the optimal process parameters.

This study used friction stir spot welding (FSSW) to weld 1.1- and 2.1-mm AA6061-T6 sheets at 560, 710, 900, and 1120 rpm at a fixed dwell duration of 5 s. It was determined how much heat was supplied into the FSSW, and the cycle temperature that occurred throughout the FSSW technique was carefully documented. Both the sheet metals and the formed FSSW weldments were subjected to micro and macrostructure analysis, as well as a lap shear test and a hardness test. A scanning electron microscope (SEM) was also used to study the cracked surfaces. A broad variety of rotation rates, ranging from 560 to 1120 rpm, were used to construct error-free spot joints, as shown by the macroanalysis. The microstructural results may show acceptable mechanical characteristics of FSSW joints, which pertain to the grain refinement of the joints’ stir zone (SZ). It was discovered that the optimal welding condition for establishing spot welds with varying thicknesses of thin sheets was 710 rpm. This was achieved with a SZ lap shear resistance of 5020 ± 20 N and hardness of 99 ± 2 HV₍₁₀₀₎. The temperature fluctuation and Von Mises stress distribution, in the AA6061-T6 FSSW sheets, were analysed by using ABAQUS/CAE 2021 software. The simulated peak temperature is rather similar to the recorded one. On the other hand, by raising the rotation speed, the peak temperature at the welded joints rose. The friction stir welding (FSW) procedures have an impact on the residual stresses; on the other hand, the welding parameters are influenced by the welding temperature and mixing.

In this study, microelectrical discharge machining (μEDM) is used for drilling microholes on a thin sheet of Ti Grade 2 alloy of thickness 50 μm using a tungsten carbide (WC) microtool of diameter 470 μm. The main focus of the study is to understand the electrical and nonelectrical μEDM parameters on the accuracy, precision, and machining efficiency of drilled holes. The controllable process factors such as capacitance, voltage, tool rotation, and feed rate are considered when conducting the experiments based on a Taguchi L16 orthogonal array. The main effect and interaction contour plots have been prepared to investigate the influence of the process parameters on the response measures like material removal rate, overcut, circularity, and taper angle of the drilled holes. Analysis of variance (ANOVA) has been carried out to study the percentage contribution and significance of each process parameter on the performance measures. The micrographic images reveal the quality of the profiles and edges of the drilled holes. Further, the Overall Evaluation Criterion (OEC) is applied for multiparameter optimization.

Foaming or porous geopolymers can be utilized in various engineering applications, including heat and acoustic insulations, as well as passive fire protection in building materials. They are ecofriendly materials, as no significant production power is required. In this study, geopolymers possessing foaming features involving lightweight and porous materials were successfully created through the reaction of sodium hydroxide solution 6 M with powder of waste glass MG without/with rice husk (RH) 20 wt.% of heat treated (212, 420, and 600 μm) utilized as the foaming agent. The effect of rice husk ash (RHA) and various sizes of RH additives on the thermal treatment (volume and weight changes, percentage), compressive strength, and microstructure (pore content) was assessed. The results show swelling (foaming behavior) for MG-N6, MGB-N6, MGR212-N6, and MGR600-N6 at 550°C, unlike the MGR420-N6 formula. Also, a high-volume change (percentage) for MGR420-N6 paste at 650°C was noticed. Additionally, foaming behavior (high volume expansion) appeared for all thoughtful pastes after treatment at 750°C. The weight loss for all specimens in the range of 10%–27% and a high percentage of weight changes for MGR400-N6 and MGR600-N6 were noticed. Low values of compressive strength (2.74–14.5 MPa) were recorded for all formulas studied. These synthesized materials, geopolymers containing glass waste and RH powder, resulting from this study, are highly recommended, mostly for thermal and acoustic insulation materials demanding lightweight, porosity, and low mechanical properties.

In this work, Ti-6Al-4V alloy was joined by tungsten inert gas (TIG) welding and the plates were undergone through optical microscopy test, elemental study, tensile test, hardness test, and fractographic observation. Plate-A, with low value of current input, possesses α + β bimodal structure at BM, acicular martensite at HAZ, and Widmanstätten structure with a low amount of martensite at the WZ. Plate-B, with comparatively higher value of current during welding, possesses similar structure at the BM. The HAZ area was comparatively lesser with significant martensite formation, and the WZ contains considerable formation of Widmanstätten structure. The elemental composition of BM and WZ was established by EDS. The stress-strain curves for both plates show that plate-B has almost 3%, 8%, and 7% greater UTS, YS, and elongation, respectively, than plate-A. The significant formation of Widmanstätten structure has made the WZ of plate-B more ductile and tough, although the fractography analysis of both the plates has shown macrodimples and flowing sign of metal as indicators of good ductility.