Maximum Ultimate Tensile Strength Research Articles

An experimental study on jute/banana fiber reinforced poly(vinyl alcohol) composites with nanofiller

AbstractThe incorporation of nanoparticles into natural fiber composites has the potential to alter the characteristics of natural fiber composites. In this study, various properties of jute and banana fiber reinforced poly(vinyl alcohol) (PVA) composites with different nanofillers incorporation were investigated. Samples were prepared using the vacuum bagging technique. Inorganic nanoparticles (Al2O3, ZnO, MgO, CuO, and TiO2) were synthesized using a ball milling machine and in each sample, 3 wt.% of nanofillers were incorporated. The maximum ultimate tensile strength and elongation percentage is found for TiO2, which is 90.433% higher than pure PVA whereas MgO incorporated samples provides maximum flexural strength, which is 162.59% higher than PVA. The sample with Al2O3 provides strongest impact resistance, 17.3 J/cm2. It was found that the decomposition temperatures were slightly higher for MgO and CuO doping than the undoped PVA composite. The FT‐IR spectra exhibited notable hydroxyl groups and minor shifts indicating a reduction in hydrophilicity upon the introduction of nanoparticles. The water absorption exhibited a reduction of up to 36% in conjunction with an increase in density across all samples. The highest crystallinity is found for CuO nanofiller composite, validated by x‐ray diffraction analysis. Additionally, morphological changes in the composites were seen through scanning electron microscopy and EDX shows a strong peak at 2.1 keV indicate some impurities present in the samples.Highlights Jute/banana/PVA composites were prepared with 3 wt% nanoparticles incorporation. Metal oxides such as Al2O3, ZnO, MgO, CuO, and TiO2 were used as nanoparticle. The use of nanoparticle improved the tensile, flexural, and impact properties. Decomposition temperatures were found higher for MgO and CuO incorporated composites. Upon nanoparticle incorporation, water absorption exhibited a reduction of upto 36%.

Analysis of thermal stability and mechanical properties of nanocrystalline ultra-thin Ni–Co foils

In this study, nanocrystalline ultra-thin (NUT) Ni and Ni–Co foils were prepared using electrodeposition with varying Co content. Their composition and microstructure were characterized. A systematic investigation was conducted to the thermal stability and mechanical properties of NUT foils. The results indicated that with an increase in Co content, there was an increase in the driving force for grain growth and a decrease in grain boundary (GB) energy, resulting in unexpected improvement in the thermal stability despite the decrease in grain size. The incorporation of Co enhanced the strength of the NUT foils. However, the effect of increased Co content on the improvement in strength was relatively small. Due to its extremely thin thickness and nanocrystalline microstructure, the ultimate tensile strength (UTS) and elongation (EL) of the NUT foil fell below the theoretical strength, while the maximum UTS and EL were observed at a Co content of 17 %, which exhibited a UTS of 1337 MPa and an EL of 8.6 %. The tensile fracture exhibited a clear combination of brittle and ductile modes. With an increase in Co content, the NUT foil transitioned from predominantly brittle to ductile and then back to brittle fracture.

Effects of heat treatments on the microstructure and mechanical properties of Inconel 718 alloy fabricated by electron beam freeform fabrication

The present study investigated the effects of different heat treatments on the microstructure and mechanical properties of Inconel 718 alloy fabricated by electron beam freeform fabrication. The Laves phases, γʹ phases, and (Nb,Ti)C particles were precipitated in the as-deposited specimen. Solution at 960 °C promoted the partial dissolution of Laves phases and the precipitation of δ phases. Further increasing the solution temperature to 1060 °C dissolved the Laves phases effectively, facilitating the adequate precipitation and uniform distribution of γʹ and γʹʹ phases during the subsequent double aging heat treatment. The ultimate tensile strength (UTS) and elongation of the as-deposited specimen were 770 MPa and 12.2 % respectively. The solution heat treatment at 1060 °C increased the elongation to 38.1 % but decreased the UTS to 734 MPa. The microhardness and UTS of specimens that underwent double aging heat treatment were significantly increased, with the maximum average microhardness and UTS reaching 491 HV0.5 and 1285 MPa, respectively. The undissolved Laves phases and the precipitated δ phases at grain boundaries impaired the ductility. The transformation from single solution or double aging heat treatment to solution plus double aging heat treatment led to a shift from a ductile fracture mode to a mixed ductile and brittle fracture mode.

Microstructure, mechanical properties and corrosion resistance of direct energy deposited AlCu0.25CoCrFeNi2.1 high entropy alloy: Tailored by annealing heat treatment

In this study, a novel high entropy alloy AlCu0.25CoCrFeNi2.1 is additively manufactured by laser direct energy deposition process. The microstructure, mechanical properties and corrosion resistance of the prepared AlCu0.25CoCrFeNi2.1 high entropy alloy are investigated and tailored by annealing heat treatment. The results indicate the alloy exhibits a dual-phase microstructure with face-centered cubic (FCC) columnar dendrites and body-centered cubic (BCC) interdendritic structures. The annealing heat treatment facilitates the precipitation and coarsening of Cu-rich short rod-like B2 phase within the incipient FCC phase and the dissolution of incipient BCC phase, synergistically varying the proportion of FCC/BCC + B2 contents and tailoring the properties. The hardness of microstructure fluctuates under the coupling effect of precipitation strengthening and lattice distortion reduction and shows an overall downward trend with the increase of annealing time. The tensile properties are noteworthily improved within 6-h annealing and achieve a maximum ultimate tensile strength of 1156.4 MPa. After 8-h annealing, the ductility of the alloy obtains a maximum value of 30.3% with minor loss of ultimate tensile strength. The corrosion resistance is dramatically enhanced and obtains the best value after 2-h annealing, and then gradually deteriorates with the destroying of FCC matrix passive film phase by coarsened B2 phases. These results are of great importance in rapidly designing/manufacturing novel high entropy alloys by laser direct energy deposition process and tailoring microstructure, mechanical properties and corrosion resistance by annealing heat treatment.

Injection Molding Condition Effects on the Mechanical Properties of Coconut-Wood-Powder-Based Polymer Composite.

This study investigates the mechanical properties of coconut sawdust powder combined with polypropylene (PP). The effect of compatibility content, wood powder (WP) content, and injection molding parameters on the properties of coconut wood powder composite (WPC) is evaluated. The results could be used to figure out the optimal mechanical properties such as tensile strength, elongation, elastic modulus, and flexural strength by selecting suitable parameters and composition. The bonding between the WP particles and the PP matrix is good, and the WP is uniformly distributed across the composite matrix, as indicated in the scanning electron microscopy (SEM) results. Interestingly, with the presence of the compatibilizer oleamide, increasing the WP content from 20 wt.% to 40 wt.% did not result in WP accumulation in the composite matrix. Notably, at 20 wt.% WP, the elongation is the highest (at 7.40 wt.%), while at 30 wt.% WP, the elastic modulus reaches the highest value. The maximum ultimate tensile strength (UTS) value is obtained at 35 wt.% WP. Higher WP mostly results in greater flexural strength and shore D hardness. At 40 wt.% WP, the WPC achieves its peak shore D hardness of 77.6. The Taguchi results suggest that WP content is the most critical factor in the UTS value of coconut WPCs. The filling pressure ranks second, followed by the packing pressure. Finally, unlike the other characteristics, the melt temperature has a minimal impact on the UTS value.

Effect of Friction Coefficient in Friction Stir Welding of B4C Reinforced AA5083 Metal Matrix Composites and Use of Fuzzy Clustering Technique for Weld Strength Prediction

The friction stir welding (FSW) method was used to weld B4C reinforced AA 5083 metal matrix composites in this study. By coating titanium nitride (TiN), aluminium chromium nitride (AlCrN), and diamond-like carbon (DLC) to a thickness of 4 microns, three FSW tools with square pin profiles were developed and the friction coefficients of 0.69, 0.32, and 0.2 were maintained. At three levels, the process factors such as tool rotating speed, transverse feed, and axial force were examined. For each tool, 15 samples were made using the central composite design. The influence of the friction coefficient on ultimate tensile strength, microstructural features, and tool condition was studied, and the flower pollination algorithm (FPA) technique was used to find the best process parameters for obtaining maximum ultimate tensile strength of FSW joints. The improved tensile strength of FSW joints was verified using a validation test. The coating has a considerable influence on the ultimate tensile strength, microstructure, and tool condition, according to the results of the tool’s friction coefficient. The results on the prediction of strength using the fuzzy clustering technique showed that the technique is effective in predicting the tensile strength values, with the root mean square error (RSME) of TiN, AlCrN, and DLC being 0.0027, 0.0016, and 0.0015, respectively, and the low RSME indicating that the prediction based on the fuzzy subtractive clustering technique is perfect and effective.

Effect of material position and tool offset on the microstructure and mechanical properties of friction stir welded AA7075/AZ31B with ultrasonic assistance

The primary focus of this study is to analyze how changes in material position and tool offset affect the microstructure and mechanical properties of dissimilar alloys (AA7075/AZ31B) joints. The study specifically examines these effects in normal and ultrasonic-assisted friction stir welded (UVaFSW) aluminum and magnesium-based joints. The experiment showed that the sound weld was achieved only when the AA7075 plate was placed on the advancing side (AS). The metallographic analysis showed that the use of ultrasonic vibration increased the flow of material in the nugget zone (NZ) and improved the length of interpenetration at the interface. Moreover, the intermetallic compound (IMC) layer thickness decreased throughout the interface during UVaFSW, improving joint strength. The maximum ultimate tensile strength was obtained at 1 mm tool-off condition for UVaFSW, i.e., 112.40 ± 7.24 MPa. Ultrasonic vibrations reduced the IMC thickness by up to 78 % at the middle of the joint interface. The fracture surface showed the ductile fracture mode in the case of UVaFSW compared to the FSW process. The current study establishes the framework for optimizing and controlling the welding process of dissimilar AA7075/AZ31B alloys, which possess considerable potential for use in the aviation industry.

Optimizing strength of directly recycled aluminum chip-based parts through a hybrid RSM-GA-ANN approach in sustainable hot forging.

Direct recycling of aluminum waste is crucial in sustainable manufacturing to mitigate environmental impact and conserve resources. This work was carried out to study the application of hot press forging (HPF) in recycling AA6061 aluminum chip waste, aiming to optimize operating factors using Response Surface Methodology (RSM), Artificial Neural Network (ANN) and Genetic algorithm (GA) strategy to maximize the strength of recycled parts. The experimental runs were designed using Full factorial and RSM via Minitab 21 software. RSM-ANN models were employed to examine the effect of factors and their interactions on response and to predict output, while GA-RSM and GA-ANN were used for optimization. The chips of different morphology were cold compressed into billet form and then hot forged. The effect of varying forging temperature (Tp, 450-550°C), holding time (HT, 60-120 minutes), and chip surface area to volume ratio (AS:V, 15.4-52.6 mm2/mm3) on ultimate tensile strength (UTS) was examined. Maximum UTS (237.4 MPa) was achieved at 550°C, 120 minutes and 15.4 mm2/mm3 of chip's AS: V. The Tp had the largest contributing effect ratio on the UTS, followed by HT and AS:V according to ANOVA analysis. The proposed optimization process suggested 550°C, 60 minutes, and 15.4 mm2 as the optimal condition yielding the maximum UTS. The developed models' evaluation results showed that ANN (with MSE = 1.48%) outperformed RSM model. Overall, the study promotes sustainable production by demonstrating the potential of integrating RSM and ML to optimize complex manufacturing processes and improve product quality.

Effect of extrusion speed on properties of Cu−5vol.%Ti2SnC composite wire fabricated by friction stir back extrusion process

The effect of axial traverse speed of friction stir back extrusion (FSBE) process on the microstructure, mechanical, electrical, and wear properties of Cu−Ti2SnC composite wire was investigated. The FSBE process was performed on the primary composite made by the powder metallurgy method with 5 vol.% of Ti2SnC MAX phase. The results showed that as the extrusion speed increased, the twins formed in the microstructure increased, the Ti2SnC particles became finer, and the interface of bonding of the MAX phase−Cu matrix improved. The Cu−Ti2SnC composite wire fabricated at the rotational speed of 600 r/min and axial traverse speed of 25 mm/min showed the maximum hardness, yield strength, and ultimate tensile strength of HV 132.7, 278.34 MPa, and 485.15 MPa, respectively. This finding was due to its strong interfacial bonding and fine MAX phase particles. Besides, the larger grain size, the better interface bonding, and the lower the porosity resulted in the highest electrical conductivity of 89.21% (IACS) and least wear rate of 0.0015 mg/m of Cu−Ti2SnC composite wire fabricated at rotational speed of 600 r/min and axial traverse speed of 25 mm/min.

Cold-welded joint characteristics of gold nanowires via atomistic simulation

This study examines the effects of contact depth, contact orientation, contact angle, and nanowires temperature on the tensile strength of the gold nanowire generated via the cold welding process. There is an increase in the deformation rate with increasing contact depth. From 5 Å to 20 Å, the lattice matching of the nanowires is good, leading to a good weld joint. The greatest ultimate tensile strength (UTS) value is achieved at 5 Å contact depth compared to other depth cases. The UTS value is sensitive to the change in the contact orientation and the contact angle. Compared to other orientations, the (001) vs (001) orientation has the highest rate of orientation matching with the highest FCC structure ratio. Other orientations obtain a much lower UTS value. When the contact angle rises, the UTS value mainly decreases due to the higher level of lattice mismatch. Compared to the other angle cases, the maximum UTS value is attained at 0º contact angle. Moreover, changing in nanowires temperature within the 250 K450 K range do not result in significant variations in the sample's surface morphology, structural transformation, or atomic strain. At 250 K, the sample has the highest UTS value compared to other temperature cases.

An innovative pulsed current arc welding technology for armor steel: Processes, microstructure, and mechanical properties

This study presents a novel pulsed current arc welding technology, specifically pulsed current gas tungsten arc welding (PC-GTAW), single and double pulse gas metal arc welding (SP/DP-GMAW), and dual process welding (D-process). This study aims to investigate the effectiveness of these welding techniques for armor steel weldments. This research focused on investigating the welding processes, resulting microstructures, and mechanical properties of welded joints. Based on the macrography analysis, it was determined that the weldments exhibit no signs of porosity, inclusions, or inadequate penetration. This finding substantiates the optimum settings for the weldment production process. The weldment optical microstructure, fusion, and heat-affected zone were examined in the weld interface. The microstructural properties of the FZ include δ-ferrite, austenite, bainite, and acicular martensite. The HAZ has a bainite-untempered martensite microstructure. The chemical composition and variations across the weldment (base, weld and HAZ) were identified. The grain borders contained greater quantities of Cr, Ni, Mn, Si, and Mo than those of the grain cores. EBSD revealed average weld zone grain sizes of 17.7 µm, 32.6 µm, 30.8 µm, and 24.6 µm for PC-GTAW, SP-GMAW, DP-GMAW, and D-Process, respectively.Furthermore, the hardness measurements showed a progressive transition across different regions. Additionally, the D-Process-fabricated material exhibited a maximum ultimate tensile strength of 872 MPa and an elongation of 4%. The mechanical properties exhibited by this new process variant exceed those of other weldments, indicating its potential for fabricating armor steel. The impact toughness demonstrated superior performance in all the weldments. Within this context, the new use of pulsed current advanced welding methods has shown the ability to generate welded parts of exceptional quality.

Mechanical, electrochemical corrosion, and high-temperature oxidation properties of stir-cast and heat-treated AZ80 magnesium alloy

This study aims to produce a stir-cast AZ80 magnesium alloy and to correlate the phases and microstructure of the as-cast, T4, and T6 conditions with the alloy's mechanical, corrosion, and oxidation properties. Microstructure was analysed using Field Emission Scanning Electron Microscopy (FE-SEM) with Energy Dispersive Spectroscopy (EDS), Electron Backscatter Diffraction (EBSD), and High-Resolution Transmission Electron Microscopy (HRTEM), and X-ray diffraction (XRD) technique was employed to examine at the alloy’s phases. A Vickers microhardness, tensile, and impact test specimens were meticulously prepared according to ASTM specifications. The electrochemical corrosion was tested in 0.6 M NaCl and 0.05 H2SO4, simulating the salty seawater and low-sulphur air environments. Based on the eutectic temperature of the Mg-Al alloy system, which is 437 ℃, the high-temperature oxidation test was carried out at 400 ℃, 410 ℃, and 420 ℃. Microstructural study confirms that both T4 and T6 alloys undergo grain coarsening with a grain size of 72.64 µm, and the orientation of the grains shifted from the pyramidal plane (2−1-10) to the basal plane (0001). The TEM investigation helps pinpoint the GP zone's genesis in T4 heat-treated AZ80. T4 AZ80 has a maximum ultimate tensile strength of 306 MPa and a ductility of 29.77% because of the dispersion-strengthening effect. The T6 AZ80, on the other hand, has a minimum corrosion rate of 0.158 mm/year in NaCl solution and an oxidation rate constant of 4.19 mg2.cm−4h−1 at 420 ⁰C. Notably, the T6 AZ80 shows significant peaks of Mg2Al3, and the as-cast shows more peaks of Mg17Al12. Magnesium alloy AZ80 is significantly affected by intermetallic phases like Mg17Al12 and Mg2Al3. The Mg2Al3 phase shows the latter tendency to resist corrosion and oxidation.

Tensile behavior of high-strength highly ductile fiber-reinforced concrete with embedded carbon textile grids

Highly ductile fiber-reinforced concrete (HDC) exhibits good cracking patterns and tensile strain-hardening characteristics. Recently, a high-performance HDC was developed and named the high-strength HDC (HSHDC). Compared with ordinary HDC, HSHDC exhibits higher ultimate tensile strain (exceeding 8 %) and higher compressive strength (exceeding 100 MPa). In this study, HSHDC is applied to fabricate composites with textiles, which is named textile-reinforced HSHDC (TR-HSHDC). The main purpose is to further significantly improve the tensile strength of HSHDC to meet higher functional requirements. Thus, fifteen TR-HSHDC specimens and twelve textile-reinforced HDC (TR-HDC) specimens, and nine non-reinforced specimens were tested under uniaxial tensile loads. The test variables were the carbon textile reinforcement ratio, volume content of short fibers, and strength of matrices. The crack patterns, failure modes, stress-strain curves, and mechanical property parameters were analyzed and discussed. The test results showed that the TR-HSHDC specimens require more short fiber to exhibit multiple cracking than the TR-HDC specimens. The maximum ultimate tensile strength of the TR-HSHDC specimen with a textile reinforcement ratio of 1.05 % was up to 22.43 MPa. The stress-strain curve of the specimens can be classified as a five-stage or three-stage type by adapting the matrix type, content of short fibers, and textile reinforcement ratio. Besides, a two-stage nonlinear model was presented to predict the ultimate tensile strength and describe the stress-strain relationship of such composites.

A comprehensive study of ultrasonic-assisted gas metal arc welding of high-strength steel

The present study investigated longitudinal ultrasonic vibrations applied uniformly perpendicular to the weld line as an efficient approach in the ultrasonic-assisted gas metal arc welding (U-GMAW) of high-strength steel. The penetration depth, microstructure, microhardness, mechanical properties, and corrosion of welded joints produced from GMAW and U-GMAW were experimentally explored at different welding conditions to evaluate their performance. The experimental findings show that welded joints produced by U-GMAW have a maximum ultimate tensile strength (UTS) of 18.7 %, while showing 35.4 % elongation and 57.4 % toughness compared to the GMAW-welded joints at optimal conditions. The surface morphology analysis of the welded joints emphasizes that the dendritic microstructures generated by U-GMAW are finer than the dendritic microstructures generated by GMAW. Moreover, the microhardness of welded joints produced by U-GMAW method is higher than the GMAW-welded joints. The results of the polarization test also confirm that the corrosion rate of GMAW-welded and U-GMAW-welded joints are 360 and 1.60 µm/year, respectively with a power of 30 %. These results show that the corrosion rate of welded joints produced by GMAW is much higher than the one produced by U-GMAW.

Enhanced strength in Pt–25Au–25Cu–25Ni medium-entropy alloy by a combination of cold working and aging

Precious metals and alloys are widely used in the aerospace industry and microelectronic devices due to their excellent chemical stability and electrical properties. However, the expensive price limits their broad use. The multi-principal element approach shows the ability to reduce the cost and retain desirable properties. Therefore, a precious metal medium entropy alloy, Pt–25Au–25Cu–25Ni, was designed and prepared, and the effect of annealing temperature on the microstructure and mechanical and electric properties of Pt–25Au–25Cu–25Ni alloy was studied. The alloy is a face-centered cubic phase after annealing at temperatures above 850 °C. The decomposition along the grain boundaries occurs after annealing at temperatures 400–750 °C. After annealing at low temperatures, the cold-deformed alloy shows a significant age-strengthening effect, whereas the solution-treated alloy does not. The hardness of the solution-treated alloy stabilized around 225 HV. But aging of cold-deformed samples at 400 °C for 1 h showed the maximum ultimate tensile strength and hardness of 1497 MPa and 454 HV, 179 MPa and 56 HV increased compared with the cold-deformed alloy. The TEM results show that the nanosized L12 ordered phase formed during aging at low temperatures, and acts as an aging strengthening phase. And the cold deformation promotes the L12 phase formation during aging. Meanwhile, the electric resistivity of cold-deformed samples after aging at low temperatures decreases in a large stage. The lowest value appeared as 53.36 μΩ cm.

Bo-derived waste neem to enriching reinforced hybrid composite for environmental remediation

The utilization of natural fibres often entails a lesser environmental impact when compared to synthetic fibres. Biodegradable natural fibres minimize waste and pollution, and promote sustainability, but their weaker bonds limit their resilience. These issues can be addressed by customizing the composite's mechanical properties with natural and synthetic fibres. In this study, hybrid composites were created using the hand layup method with a novel dissimilar layer arrangement of neem (N), sisal (S), and glass (G) fibre and analyze its mechanical and thermal properties. Experimental observation shows that the GN composite had a higher maximum ultimate tensile strength of 26 N/mm2 than the GS, GNS, and GSN composites. The GN composite had a percentage elongation of 6.33%, similar to the percentage elongation of the GS composite (6.833%), and it also had a higher ultimate shear strength of 50 MPa. The composite GS absorbed 6.6 J energy, higher than the composites GN, GNS, and GNS, which absorbed 6.1 J, 4.5 J, and 4.5 J, respectively. The fractured surface's SEM images were obtained and analyzed for failure. The results demonstrated that the hybridization was effective, and better properties can be obtained by combining neem, sisal, and glass fiber, and it can be used for other requirements, including strength, weight, cost, and ecological impact.

Investigating the microstructure and mechanical behavior of optimized eutectic Al[sbnd]Si alloy developed by direct energy deposition

Wire arc additive manufacturing (WAAM) is a direct energy deposition process majorly used to fabricate large and medium-sized components. However, the process encounters defects, such as anisotropic microstructure and mechanical properties, residual stresses, excessive oxidation, and geometrical irregularities. Hence, efforts have been made to address the issues by optimizing the process parameters and incorporating in situ and post-process treatment to improve mechanical properties. In line with this, the present work deals with statistical-based process parameter optimization based on a multicriteria approach. The responses were quantified, statistically analyzed, and correlated with the process parameters. Travel speed exhibited a minor effect on all responses, while the current and wire feed speed significantly affected the responses. The percentage porosity was more sensitive to welding current than the other parameters. The maximum ultimate tensile strength (UTS) of 193.73 ± 3.93 MPa and yield strength (YS) of 108.09 ± 12.28 were displayed by Wall 2. YS and UTS showed marginal variation in vertical and horizontal directions, while % elongation showed significant variation. The desirability Wall (DW) exhibits better-forming quality due to the minimization of the contact angle, and fibrous silicon was observed between the layers. In contrast, it appears to be fragmented silicon at the interfacial region due to remelting and breakdown of Si. However, there were a few limitations to the DW wall's mechanical properties due to coarser dendrites and bulk eutectic at the interface. The average grain size of the bottom and top region for the optimized parameter is 111.156 μm and 173.66 μm, respectively. The observed texture components in the top region include C{001} 〈110〉, A2* (111) [112¯], A (11¯1) [110], and B (11¯2) [110], exhibiting a maximum texture intensity of 10.414. In the bottom region, the identified texture components are B¯ (1¯12¯) [1¯1¯0], B (11¯2) [110], A (11¯1) [110], C{001} <110> with a maximum texture intensity of 10.110.

Depth-dependent microstructure and mechanical properties of hot rolled AA7075

In this study, the through-thickness mechanical properties of a 32 mm thick hot rolled 7075 aluminum plate were measured with microscale uniaxial tensile tests. The mechanical strength across the thickness of the plate exhibited a complex M-shaped profile, with the maximum yield strength and ultimate tensile strength of 440.45 MPa and 493.81 MPa respectively attained at 11 mm depth from the surface of the plate. Representative samples from 0, 4, 11 and 16 mm depths were investigated to understand the influence of the precipitate distribution on the evolution of through-thickness mechanical properties in this alloy. The size and distribution of the microscale (>50 nm) and nanoscale (<20 nm) precipitate phases were quantified with a combination of large area scanning electron microscopy (SEM) and small angle x-ray scattering (SAXS) techniques and correlated with through-thickness mechanical properties obtained through microscale tensile testing. The nanoscale precipitate density as investigated with SAXS showed that the 11 mm depth had the highest volume fraction (0.0086) in comparison to the other representative depths. Moreover, the quench and temper processes were modeled using the precipitation module of Thermo-Calc with various assumptions about cooling rate and microstructure and they were found to be in good agreement with the experimental findings.

Investigation of mechanical characteristics of coir fibre/hexagonal boron nitride reinforced polymer composite

Coir fibre, derived from the husk of coconuts, is a natural resource and they are biodegradable and renewable. By incorporating them, any product can become more lightweight and durable, meeting the global desire for eco-friendly and efficient designs. This study has the potential to significantly alter the design of components such as switches and enclosures and it has an international research impact on engineering applications. Coir fibres and Hexagonal-Boron Nitride (h-BN) possess superior mechanical, thermal and physical qualities when reinforced with polymers. Hence novel study is carried out to examinecoir fibre/h-BN reinforcement in epoxy polymer composites. Response Surface Methodology via Box-Behnken Design (BBD) is utilized to investigate the mechanical properties such as Tensile Strength, Impact Strength and Young’s Modulus of coir fibre/h-BN reinforced epoxy polymer composite. The effect of input parameters onresponse is evaluated through regression equation and analysis of variance by using statistical Minitab software. The response optimization represents the maximum Young’s modulus (1597 MPa) by combining coir fibre (5 wt%), Coir fibre powder size (75 μm) and h-BN (1 wt%). The response optimization portrays the maximum Ultimate Tensile strength(36.83 MPa) by combining coir fibre (1 wt%), coir fibre powder size (220 μm) and h-BN (3.78 wt%). The response optimization reveals the maximum Impact strength (98.35 J m−2) by combining coir fibre (5 wt%), coir fibre powder size (225 μm) and h-BN(1 wt%). This work emphasises the use of composite materials that are environmental friendly in a variety of industries such as automotive, electrical, etc.

Influence of Graphene on the Microstructure and Mechanical Properties of Aluminium Matrix Composite

The constraints of conventional aluminum alloys have prompted the investigation of strengthening substances such as carbon nanotubes and graphene fillers. The improved composite exhibits suitability for applications in the automotive and aviation industries. Graphene's popularity stems from its high strength, electrical and thermal conductivity, and chemical inertness, making it ideal for mechanical, thermal, and microstructural applications. This research varied concentrations of graphene nanoplatelets (0.3%, 0.6%, and 0.9%) to enhance the mechanical properties of aluminum metal matrix composites. A stir casting process was employed to create a graphene-reinforced aluminum matrix composite using A356 aluminum alloy. A designed experiment (DOE) investigated the impacts of graphene concentration and suitable heat treatment time on the aluminum composite. Subsequently, the specimens underwent heat treatment and X-ray diffraction (XRD). Mechanical properties were examined using a universal testing machine. The best aluminum matrix composites were produced with 0.9wt% graphene and 180 minutes of heat treatment. These parameters resulted in a microstructure with refined grains evolving from dendritic to rosette. The grains became closely packed, and reduced porosity was observed. As a result, the mechanical properties were enhanced, with a maximum ultimate tensile strength (UTS) of 250 MPa and a fracture elongation of 6%. The findings indicate that graphene nanoplatelet (GNP) concentration significantly influences the mechanical characteristics of the composite. Tensile and yield strength increase with GNP concentration, but higher concentrations reduce the composite's ductility. These insights contribute to optimizing GNP-reinforced composites and developing innovative materials with superior mechanical properties.