Tensile Strength Values Research Articles

Thermo-mechanical characteristics of spent coffee grounds reinforced bio-composites

Abstract This research examines the incorporation of spent coffee grounds (SCGs) into composite materials utilizing a three-part system composed of modified castor oil, polyester resin, and SCGs. The objective is to assess the mechanical, microstructural, and thermal characteristics of the resultant composites. The composite specimens underwent a thorough preparation and were tested through a battery of procedures comprising tensile testing, shore D hardness testing, SEM, FT-IR, and thermal conductivity measurements. Tensile testing revealed higher mechanical resilience, reinforcing the desirable properties of SCGs. The 5 % SCG-reinforced sample exhibited the highest tensile strength value, with a 41.85 % increase observed in comparison to the pure sample. The results of shore D hardness tests demonstrated that there was no significant change in material hardness up to 3 % additive content. However, a decrease in hardness was observed at higher additive rates. At a 7 % additive rate, there was a 2.82 % decrease in material hardness. Furthermore, the application of scanning electron microscopy (SEM) analysis has revealed the microstructural features of the composite matrix, which have highlighted the distribution of SCGs within it. The successful implementation of SCGs has also been verified by means of Fourier transform infrared (FT-IR) analysis. Finally, based on thermal conductivity measurements, it has been determined that SCGs are suitable for thermal insulation purposes. This study represents a significant contribution to the field of sustainable materials science, emphasising the potential benefits of SCGs in improving the effectiveness of composite materials.

Effect of pre-induced precipitations on microstructure evolution and the mechanical properties of pre-twinned ZK61 Mg alloys at elevated temperatures

To examine the effects of pre-induced precipitations on microstructure evolution and mechanical properties of pre-twinned ZK61 Mg alloy at elevated temperatures, the commercially rolled ZK61 Mg alloy sheets (AR samples) were pre-twinned and {10−12} tensile twins were added (PT samples). Some samples were aged, precipitated phases were introduced (PTA samples), and subsequently uniaxial tensile strain was applied. The results reveal that at elevated temperatures, the interactions of detwinning, dynamic recrystallization (DRX), and precipitation have a distinctive impact on the microstructure evolution. At room temperature (RT) and 100 ℃, strain is dominated by detwinning, while the precipitation phase impedes the detwinning behaviors. DRX influences the evolution of the microstructure at 150 ℃, 200 ℃, and 250 ℃. The presence of precipitated phases promotes recrystallization nucleation. Continuous DRX (CDRX), detwinning, and precipitated phase deformation are coordinated at 150 ℃. DRX in aged samples has a limited effect, while detwinning plays a dominant role. The ultimate tensile strength (UTS) value increment of PTA sample relative to PT sample reaches 31.8 MPa. The deformation is generated by the discontinuous DRX (DDRX) at 250 ℃, and the precipitation and DDRX have a higher impediment on detwinning, resulting in more twins restraining in the PTA sample. The UTS value of PTA sample only increases by 7.7 MPa compared with PT sample.

Fabrication and Characterization of Nickel‐Aluminide Cladding by Dual‐Wire Arc Additive Manufacturing

Nickel aluminide is a widely utilized intermetallic compound, prized for its high strength, low density, and resistance to both corrosion and creep. This study investigates the impact of heat input during the fabrication of nickel‐aluminide intermetallic compounds using the dual‐wire gas tungsten arc welding process. The results indicate that an increase in clad layer dilution from 28.9% to 33.4% reduces the amount of aluminum in the molten pool from 32.46 to 21.96 wt% while increasing the presence of the Ni3Al phase. Additionally, the NiAl phase decreases when moving from the upper side of the coating to the fusion line. When the arc current is increased from 110 to 150 A, a coarse dendritic structure forms, and the dendritic arms increase from 2.6 ± 0.4 to 5.5 ± 0.3 μm. This increase in current also results in yield strength and tensile strength values of 500.21 ± 14.56 and 752.32 ± 25.12 MPa, respectively, representing decreases of 15.2% and 5.1%. Furthermore, as the arc current increases from 110 to 150 A, both the friction coefficient and the wear rate increase to 0.43 and 0.29 ± 0.02 μg m−1, respectively. However, corrosion resistance improves by 66.3%.

Synthesis and characterization of TiNbZrMo medium-entropy bio-composites: Microstructure, mechanical properties, and in vitro degradation.

This study reports the synthesis and characterization of hydroxyapatite (HA)-based bio-composites reinforced with varying amounts (by weight, 1-15 wt.%) of bio-medium entropy alloy (BioMEA) for load-bearing implant applications. BioMEA powders consisting of Ti, Nb, Zr, and Mo were mechanically alloyed for 100 h and subsequently added to HA using powder metallurgy techniques. To show the effect of BioMEA, the microstructure, density, and mechanical tests have been conducted and the synthesized BioMEA was characterized by scanning electron microscope (SEM), x-ray diffractometer (XRD), and Fourier-transform infrared spectroscopy (FTIR) analysis. In addition, in vitro degradation behavior and bioactivity analyses of bio-composites have been conducted. XRD analysis revealed the formation of BioMEA after 20 h of mechanical alloying. The highest density value of 2.47 g/cm3 was found in 15 wt.% BioMEA-reinforced bio-composite. The addition of BioMEA reinforcement led to a significant increase in hardness and tensile strength values, with the highest values observed at 15 wt.% reinforcement. Compression tests demonstrated a significant increase in compressive strength and deformation capability of the bio-composites with the highest values observed at 15 wt.% BioMEA addition. The highest toughness of 7.68 kJ/m2 was measured in 10 wt.% MEA-reinforced bio-composites. The produced bio-composite materials have an elastic modulus between 3.5-5.5 GPa, which may provide a solution to the stress shielding problems caused by the high elastic modulus of metallic implant materials. The most severe degradation occurred in 15 wt.% MEA-reinforced bio-composites, and the effect of degradation caused a decrease in Ca and an increase in Ti-Ni-Zr-Mo in all bio-composites. These findings suggest that HA/BioMEA bio-composites have the potential to be developed as advanced biomaterials with moderate mechanical and biological properties for load-bearing implant applications.

Formulation of Saxagliptin Oral Films: Optimization, Physicochemical Characterization, In-Vivo Assessment, and In-Vitro Real-Time Release Monitoring via a Novel Polyaniline Nanoparticles-Based Solid-Contact Screen Printed Ion-Selective Electrode

Oral dispersible films have received broad interest due to fast drug absorption and no first-path metabolism, leading to high bioavailability and better patient compliance. Saxagliptin (SXG) is an antidiabetic drug that undergoes first-path metabolism, resulting in a less active metabolite, so the development of SXG oral dispersible films (SXG-ODFs) improves SXG bioavailability. The formula optimisation included a response surface experimental design and the impact of three formulation factors, the type and concentration of polymer and plasticiser concentration on in-vitro disintegration time and folding endurance. Two optimised SXG-ODFs prepared using either polyvinyl alcohol (PVA) or hydroxypropyl methylcellulose were investigated. SXG-ODFs prepared with PVA demonstrated a superior rapid disintegration time, ranging from 17 to 890 s, with the fastest disintegration time recorded at 17 s. These short durations can be attributed to the hydrophilic nature of PVA, facilitating rapid hydration and disintegration upon contact with saliva. Additionally, PVA-based films displayed remarkable folding endurance, surpassing 200 folds without rupture, indicating flexibility and stability. The high tensile strength of PVA-based films further underscores their robust mechanical properties, with tensile strength values reaching up to 4.53 MPa. SXG exhibits a UV absorption wavelength of around 212 nm, posing challenges for traditional quantitative spectrophotometric analysis, so a polyaniline nanoparticles-based solid-contact screen-printed ion-selective electrode (SP-ISE) was employed for the determination of SXG release profile effectively in comparison to HPLC. SP-ISE showed a better real-time release profile of SXG-ODFs, and the optimised formula showed lower blood glucose levels than commercial tablets.Graphical

Effect of mechanical vibration on the microstructure and mechanical properties of CO2/MAG welded joint of Q345B steel

Vibration assisted welding (VAW) has emerged as a successful replacement for heat treatments of arc welds to refine grain, reduce residual stresses and distortions and thus to improve its mechanical properties. In this paper, mechanical VAW would be applied on the 8 mm thickness Q345B steel CO2/MAG filler welding, and the filler materials are solid core welding wire and flux-cored welding wire, respectively. The results show that: with the application of vibration, the proeutectoid ferrite in the weld area becomes finer, and the dendrites in the columnar crystals become significantly finer and more evenly distributed. The microhardness value of the weld zone in the welded joint with vibration is higher than that in the welded joint without vibration. The tensile strength of the welded joint increased from 502.5 MPa to 551.0 MPa at the motor speed of 2700 r/min when using solid core welding wire, increase nearly 10%. While, the tensile strength was deteriorated after the motor speed increased to 3600 r/min, which decreased to only 412 MPa, and the decreasement reached 25% comparing with the motor speed of 2700 r/min. During the VAW, the tensile strength and impact value of the welded joints fabricated by flux-cored welding wire are obviously better than that fabricated by solid core welding wire.

Exploring the Potential of Promising Sensor Technologies for Concrete Structural Health Monitoring.

Structural health monitoring (SHM) is crucial for maintaining concrete infrastructure. The data collected by these sensors are processed and analyzed using various analysis tools under different loadings and exposure to external conditions. Sensor-based investigation on concrete has been carried out for technologies used for designing structural health monitoring sensors. A Sensor-Infused Structural Analysis such as interfacial bond-slip model, corroded steel bar, fiber-optic sensors, carbon black and polypropylene fiber, concrete cracks, concrete carbonation, strain transfer model, and vibrational-based monitor. The compressive strength (CS) and split tensile strength (STS) values of the analyzed material fall within a range from 26 to 36 MPa and from 2 to 3 MPa, respectively. The material being studied has a range of flexural strength (FS) and density values that fall between 4.5 and 7 MPa and between 2250 and 2550 kg/m3. The average squared difference between the predicted and actual compressive strength values was found to be 4.405. With cement ratios of 0.3, 0.4, and 0.5, the shear strength value ranged from 4.4 to 5.6 MPa. The maximum shear strength was observed for a water-cement ratio of 0.4, with 5.5 MPa, followed by a water-cement ratio of 0.3, with 5 MPa. Optimizing the water-cement ratio achieves robust concrete (at 0.50), while a lower ratio may hinder strength (at 0.30). PZT sensors and stress-wave measurements aid in the precise structural monitoring, enhanced by steel fibers and carbon black, for improved sensitivity and mechanical properties. These findings incorporate a wide range of applications, including crack detection; strain and deformation analysis; and monitoring of temperature, moisture, and corrosion. This review pioneers sensor technology for concrete monitoring (Goal 9), urban safety (Goal 11), climate resilience (Goal 13), coastal preservation (Goal 14), and habitat protection (Goal 15) of the United Nations' Sustainable Development Goals.

The Functionalization of Cotton Fabric Using Urtica dioica Microcapsules to Develop UV Protective Textiles

The World Health Organization (WHO) and the United Nations Environment Programme (UNEP) have highlighted the increased risk of skin cancer due to exposure to UV radiation. This emphasizes the importance of safeguarding the skin. Although sunscreens are commonly used for protection their high cost, the need for frequent reapplication, and pollution in coastal areas necessitate alternative solutions. Clothing also offers protection but requires additional application of dyes and finishes for prolonged effectiveness. The application of synthetic or natural dyes can enhance the UV protection properties of the fabric but Synthetic dyes contribute to pollution, while natural dyes lack durability. Addressing these challenges, this study focuses on providing a durable and sustainable solution for enhancing the UV protective properties of cotton fabric using Urtica dioica microcapsules based on RSM design. Urtica dioica plant extract serves as the core material for the microcapsules. Design Expert software 10 has been used for the study. It was observed through software that at 4.116% concentration of microcapsules, 3% concentration of binder and a curing temperature of 113.258 °C an optimum UPF with sufficient fabric properties can be achieved. On conducting the experiments on these optimum conditions UPF, tensile strength and bending length value were found to be 277.60, 14.89 N/cm2 and 2.00 cm respectively. Results indicate that cotton fabric demonstrates excellent UV protection properties even after the 20th wash cycle. This research contributes to the ongoing quest for fabric with UV protection, emphasizing both efficacy and sustainability compared to current synthetic alternatives available in the market.

Sequential hybridisation of wire and powder-based additive manufacturing of Inconel 718: Mechanical and microstructural characterization

The present study combines the Wire-based DED (W-DED) and Powder-based DED (P-DED) to achieve a high deposition rate and higher feature resolution, respectively, within the single component. The research puts forward a novel Wire-Power (WP) Hybrid DED process, which is realized by sequential deposition of feedstock in Wire and then in Powder form. Based on the deposition-extraction combination, three sample configurations, C1 (Y-X), C2 (X-X) and C3 (Y-Z), were fabricated and characterized for the mechanical properties and microstructural aspects. OM images revealed defect-free P-DED and W-DED interface, while the EBSD analysis showed grain size variations owing to differences in the cooling rates. The Ultimate Tensile Strength (UTS) values of C1 and C2 configurations are about 132.2 and 139.7 % higher in comparison to C3. Low cycle fatigue results showed that the C2 sustained a higher number of completely reversed cycles to failure in comparison to the other configurations. The impact energy absorbed by C3 is the highest, affirming the strong W–P interface.

Optimization of process parameters of cold metal transfer arc welding of AA 6061 aluminium Alloy-AZ31B magnesium alloy dissimilar joints using response surface methodology

The fabrication of dissimilar metal joints, particularly between AA 6061 aluminum alloy (Al) and AZ31B magnesium alloy (Mg), poses significant technical challenges due to their distinct metallurgical characteristics and the inherent difficulties associated with welding such materials. These challenges include the propensity for intermetallic compound formation, thermal cracking, and differences in thermal and mechanical properties between the two alloys. Cold Metal Transfer (CMT) welding, known for its low heat input and controlled metal transfer, offers a potential solution to these issues. However, optimizing the process parameters to ensure strong, defect-free joints requires a systematic approach. This study aims to optimize CMT welding parameters using parametric mathematical modeling (PMM) to produce high-strength Al and Mg dissimilar joints and to study the effects of CMT parameters on tensile strength (TS) and weld metal hardness (WMH), as well as the microstructural features of AA 6061 aluminum alloy/AZ31B magnesium alloy (Al/Mg) dissimilar joints. Al/Mg dissimilar butt joints were produced by the CMT process using ER4043 as filler wire. CMT, a low-heat input welding technique, was used to mitigate issues such as intermetallic compounds (IMCs), wider heat-affected zone (HAZ), and distortion. The CMT parameters, particularly wire feed speed (WFS), welding speed (WS), and arc length correction (ALC), were optimized using response surface methodology (RSM) to maximize the TS and WMH of the Al/Mg dissimilar joints. Polynomial regression was employed to create PMMs that integrated these CMT parameters to forecast the TS and WMH of the joints. An analysis of variance (ANOVA) was applied to assess the feasibility of the PMMs. The results indicated that the Al/Mg dissimilar joints, produced using a WFS of 4700 mm/min, a WS of 280 mm/min, and an ALC of 10%, exhibited higher TS and WMH values of 33 MPa and 95.8 HV, respectively. The PMMs provided precise forecasts for the TS and WMH of the Al/Mg joints with an error rate of less than 1% and a confidence level of 97%.

Valorisation of Agricultural Residue Bio-Mass Date Palm Fibre in Dry-Blended Polycaprolactone (PCL) Bio-Composites for Sustainable Packaging Applications

Abstract Purpose This study experimentally developed and characterised dry-blended Polycaprolactone (PCL)/date palm fibre biodegradable composites for sustainable packaging applications. Date palm fibres are collected from date palm trees as by-products or waste materials. They will be valorised in bio-composite application to promote fibre-based sustainable packaging items over their non-biodegradable synthetic polymer based conventional packaging products. In the dry-blending process, fibre and polymer are mixed with a shear mixer, while, in a melt-blending process, an extruder is used to extrude fibre/polymer blends after applying heating and high shear pressure to melt and mix polymer with fibres. Dry-blending process offers many comparative advantages, such as less equipment, steps, cost, process degradation, energy consumption and hence, lower harmful environmental emissions; while, a proper fibre/polymer mixing is a challenge and it needs to be achieved properly in this process. Therefore, it is important to understand the effects of dry-blending process on manufacturing of PCL/date palm fibre bio-composites for packaging applications, before promoting the dry-blending as a suitable alternative to the melt-blending process. Methods Short chopped fibres were grinded as powders and dry-blended at a ratio of (0 − 10%) (w/w) with PCL polymer using hand and a shear mixer for 30 min, following a compression moulding process to produce bio-composite samples. Tensile, water contact angle, SEM, TGA, DSC and DMA tests and analysis were conducted. The dry-blended PCL/date palm fibre composites’ properties were compared with reported melt-blended samples’ results found in literature. Results Dry-blended samples showed an increase in tensile modulus values (up-to 20%) with fibre inclusion and these values were found close to the melt-blended samples in the literature. Tensile strength and strain values were reduced which could be related to the poor fibre/polymer interface. Fibre addition affected the thermal, thermo-mechanical and crystallisation processes in PCL polymer matrix. Conclusion Dry-blending is capable of producing bio-composites with a very comparable properties to melt-blended counterparts, although a more details study is needed to conduct in future. The results of this study, could be used carefully to design dry-blended PCL/date palm fibre bio-composites for possible packaging applications. The irregular fibre distribution in dry-blended samples could be improved in different ways which should be investigated in future. Graphical Abstract

Study on barrier properties, biodegradability and antimicrobial activity of linear low density polyethylene/starch blends

Purpose The present work aims to prepare biocomposites blend based on linear low density polyethylene/ starch without using harmful chemicals to improve the adhesion between two phases. Also, the efficiency of essential oils as green plasticizers and natural antimicrobial agents were evaluated. Design/methodology/approach Barrier properties and biodegradation behavior of linear low density polyethylene/starch (LLDPE/starch) blends plasticized with different essential oils including moringa oleifera and castor oils wereassessed as a comparison with traditional plasticizer such as glycerol. Biodegradation behavior forLLDPE/starch blends was monitored by soil burial test. The composted samples were recovered then washed followed by drying, and weighting samples after 30, 60, and 90 days to assess the change in weight loss. Also, mechanical properties including retention values of tensile strength and elongation at break were measured before and after composting. Furthermore, scanning electron microscope (SEM) was used to evaluate the change in the morphology of the polymeric blends. In addition to, the antimicrobial activity of plasticized LLDPE/starch blends films was evaluated using a standard plate counting technique. Findings The results illustrate that the water vapor transition rate increases from 2.5 g m−2 24 h−1 for LLDPE/5starch to 4.21 g m−2 24 h−1 and 4.43 g m−2 24 h−1 for castor and moringa oleifera respectively. Also, the retained tensile strength values of all blends decrease gradually with increasing composting period. Unplasticized LLDPE/5starch showed highest tensile strength retention of 91.6% compared to the other blends that were 89.61, 88.49 and 86.91 for the plasticized LLDPE/5starch with glycerol, castor and M. oleifera oils respectively. As well as, the presence of essential oils in LLDPE/ starch blends increase the inhibition growth of escherichia coli, candida albicans and staphylococcus aureus. Originality/value The objective of this work is to develop cost-effective and environmentally-friendly methods for preparing biodegradable polymers suitable for packaging applications.

Fabrication of mechanical durable novolac matrix composites with recycled and cost-effective candle-soot nano particles

Novolac matrix composites are crucial due to their exceptional resistance to heat, chemicals, and mechanical stress. These advanced materials find applications in aerospace, electronics, and automotive industries, providing high-performance solutions for components requiring superior durability and reliability. In this context, the microstructure, thermal, phase, and mechanical properties of the composites obtained as a result of the recycling-oriented reinforcement of the waste candle-soot (CS) reinforcement at the rate of 1 wt% to the pure novolac (PN) and shaping with the hot press method were examined in detail at first time in the literature. While microstructural properties and fracture mechanisms were investigated by scanning electron microscopy (SEM), thermal properties were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results obtained provided critical findings as the composite hardness, tensile strength, and flexural strength values were 3.28, 2.47, and 3.21 times higher than PN, respectively. CS-reinforced novolac composites made a significant contribution to the literature by introducing a novel and eco-friendly approach to enhance material properties. Their use as a filler material provided insights into sustainable novolac composites, offering potential applications in various industries, such as electronics and aerospace, with improved mechanical and thermal properties.

Enriched oil-in-water emulsions as bioactive agents for locust bean gum films: A comparative investigation

In this study, pracaxi oil (PO) and olive oil (OO) emulsions, enriched with turmeric powder (Cur) and stabilized by nanofribrillated cellulose (NFC), were developed and incorporated to glycerol-plasticized locust bean gum (LBG) dispersions. Films were obtained by solution casting, and their properties were compared, aiming to expand PO application as a potential constituent of active food packaging. The films were characterized for their morphological, structural, transparency, gas permeability, wettability, thermal, mechanical, and antioxidant properties. In relation with the plasticized LBG film, both emulsion films showed improved humidity content, surface wettability, oxygen barrier capacity, thermal stability, and mechanical properties. As for wettability, while the initial water contact angle for the LBG film was θ0 = 93.4°, values of θ0 = 105.5° and θ0 = 99.2° were determined for the LBG films incorporated with PO- and OO-based emulsions, respectively. In comparison with the LBG film, the incorporation of PO-based droplets led to an approximately 8.0% reduction in the water vapor transmission rate values. Also, in comparison with the LBG film, the LBG/NFC/PO-Cur and LBG/NFC/OO-Cur films were capable of reducing the peroxidation value of sunflower oil by 16% and 11%, respectively. Enhancements in tensile strength values of 44% and 49% were determined for the PO- and OO-based emulsion films. The emulsion films presented similar antioxidant properties and better preservation of strawberry model food than LBG and polyethylene films. The results of the comparative experiments suggested that the use of PO may be expanded as a component of active food packaging.

In-situ monitoring of additive friction stir deposition of AA6061: Effect of rotation speed on the microstructure and mechanical properties

The AA6061 alloy depositions fabricated under three rotation speeds (Ω, 450, 500 and 550 rpm) are obtained by the additive friction stir deposition (AFSD) technique in this study. The real-time temperature, force and torque during the AFSD process were monitored by a self-developed process-aware kit, helping to thoroughly investigate the influence of Ω on the microstructure and mechanical properties of the depositions. Combined with the results of the electron back scattered diffraction (EBSD) analysis on a large area (4 × 4 mm2), it is found that the grain size increases with the increase of Ω due to high heat generation. The proportion of deformation texture components reduces because of the lower strain distribution as well as the slight deformation behavior. A higher average micro-hardness is found on the 550 rpm-deposition because of the dislocation strengthening effect. Furthermore, the values of yield strength (87.8 MPa) and ultimate tensile strength (147.2 MPa) of the depositions are the highest when the Ω is the lowest (450 rpm), owing to the lowest thermal cycle. All the results are intended to provide useful guidance and a theoretical basis for producing high-performance Al-based alloys through AFSD.

Development of bioactive films loaded with extract and polysaccharide of Pinus brutia bark.

Society's interest in natural and clean products in many areas, such as food and cosmetics, has increased considerably. It has led to the development of new techniques in the packaging of products so that the wastes from the preferred products can be recycled. In this context, Pinus brutia bark was preferred within the scope of the study to transform natural wastes into functional components and use them as packaging material. P. brutia bark (PBB) samples were collected from Bursa, Turkey. PBB samples were ultrasonically extracted using various solvents (acetone, butanol, ethanol, ethyl acetate, hexane, methanol, petroleum ether, and water) and a solvent-acidic hydrolysis system. The phenolic content profile of PBB samples was determined using high-performance liquid chromatography with diode-array detection, and total flavonoid content, antioxidant capacity, and total phenolic content were determined. Chitosan-polyvinyl alcohol (CS-PVA) films loaded with polysaccharides and containing methanolic extract were developed. The physical, chemical, and mechanical properties of the films were characterized. It is known that the thickness of the films determines the mechanical properties required to maintain the integrity of the packaging during storage and transport. From the results of the study, it was concluded that the elongation at break value was higher in CS-PVA-PBB-M films (111.08%±10.46%), Young's modulus (31.74±21.37N/mm2), and tensile strength (3.01±0.50N/mm2) values were higher in CS-PVA films. In this case, it was concluded that adding proanthocyanidin to edible films gives flexibility to the films.

Role of extracted nanosilica from rice husk on the structure, property and biodegradability of low density polyethylene/starch biodegradable film

AbstractStarch blended low‐density polyethylene (LDPE) has been extensively used to produce packaging film, but it has very low mechanical properties. This work emphasises the extraction of nanosilica from rice husk as a property‐enhancing filler for producing high‐quality packaging material. Nanosilica (200 nm) was obtained by chemical treatment followed by further size reduction through cryomill. The obtained nanomaterial was found to have a high surface area (189.64 m2/g) and pore volume (.462 cc/g) with high compatibility with the other materials in the matrix. The SEM and TEM analysis indicates the uniformity in particle size of the nanomaterial with an agglomerating tendency. The X‐ray diffractometer (XRD) and fourier transform infrared spectroscopy (FTIR) analysis reveals that the obtained material is amorphous in nature. The nanomaterial is dispersed in various proportions in LDPE/starch matrix, and it is observed that the highest tensile strength (9.62 MPa) can be obtained at 1.5% nanosilica content in the matrix. A continuous increase in Young's modulus and stiffness from 372.3 to 440.12 MPa and 20 243.2 to 28 559.42 N/m, respectively, when 1.5% of nanosilica is dispersed in the biodegradable matrix. Garden soil was a better degrading medium for the sample containing 20% of starch with weight loss of 10.32% and reduction of tensile strength and tear strength values to 5.987 MPa and 99.165 N/mm respectively, in 1 year.

Effects of Zr and Y additions on microstructure and mechanical properties of cast A356 alloy

In the present work, the effects of Zr and/or Y addition on microstructure and mechanical properties of cast A356 alloy were investigated using X-ray diffractometer (XRD), differential scanning calorimetry (DSC), optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The heterogeneous nucleation effect on Zr-rich phases generated by the peritectic reaction, the increased constitutional undercooling caused by Y addition and serve as surfactant led to the grain refinement. Besides, The average size of eutectic Si reduced from 8.5 μm in the base alloy to 6.2, 1.3, and 1.7 μm with the addition of Zr/Y/Zr + Y, respectively. Zr can slightly refine eutectic Si due to the limited growth space caused by grain refinement, while Y can modify the morphology of eutectic Si from plate-like into fibrous-like through high density twins formed by the IIT mechanism. The optimal mechanical properties are obtained when Zr and Y are added simultaneously with the ultimate tensile strength, yield strength, and elongation values of 104 MPa, 201 MPa, and 7.6%, respectively. The YS and UTS increase was due to grain-refining, Si modification and precipitation strengthening. The enhancement of El was mainly caused by Si modification, which reduced the possibility of crack initiation and propagation at Si/α-Al interfaces.

Hybrid interlayer hot rolling and wire arc additive manufacturing of Al-Mg alloy: Microstructure, mechanical properties and strengthening mechanism

Considering the deformation-strengthening benefits of Al-Mg alloy and the high forming efficiency offered by wire and arc additive manufacturing (WAAM), the microstructure evolution and strengthening mechanism of hybrid interlayer hot rolling and wire arc additive manufacturing (HR-WAAM) samples have been systematically investigated in this study. The results indicate that interlayer hot rolling can effectively reduce the size and number of pores, which diminishes the stress concentration areas. Additionally, rolling deformation significantly enhances the effect of dislocation strengthening. Furthermore, a high density of dislocations can promote recrystallization to refine grain size, while also improving grain orientation, all of which contribute to better stress distribution. Due to these reasons, the strength and toughness of the alloy are notably improved. The average ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) values achieved by HR-WAAM samples were 338 MPa, 276 MPa, and 20.9%, respectively. These values represent increases of 28.5%, 41.5%, and 38.4% compared to conventional WAAM samples. These findings are expected to provide an efficient and cost-effective method for additive manufacturing (AM) of deformation-strengthened aluminum alloys.

The role of Palm Fronds Charcoal Waste Particles On Mechanical, Thermal, and Acoustic Insulation Properties of Epoxy Composite

The main objectives of the current study are to improve the mechanical, thermal, physical and sound insulation properties of an epoxy composite, in addition to reducing environmental pollution resulting from the burning of palm kernel waste, which results from annual periodic cleaning of the palms trees, which have been disposed of by burning it. Charcoal Waste Particles of Palm Fronds Base have been used for epoxy matrix as a naturalistic reinforcement particulate material, risk-free, and non-toxic to enhance its features. The charcoal waste particles have been used in weight rates of 0, 2.5, 5, 7.5, and 10%. As stated by the results, the reinforcement process by charcoal waste particles increased the tensile strength value from 8.78 MPa to 13.64 MPa, with a 55%, and increased the elastic modulus value from 0.67MPa to 3.63MPa, with a rate 437%. Moreover, additionally, increased the bending strength from 0.1MPa to 0.64MPa, with a 540%, the hardness value increased from 58.87 to 74 (Shore D No) with a rate 26%, as well as the wear rate has been decreased. Thermal conductivity has dropped by 30% from the pure sample’s value of 0.15W/m. °C to 0.11W/m. °C. Concerning the Acoustic insulation’s, the results demonstrate that the specimens decreased the transferred acoustic energy levels from 103.3 to 95.2dB with rate 8%, with regard to the density of the prepared specimens it has been decreased from 1.55g/cm3 to 1.35g/cm3 and the results show that the liquid absorption rates have been decreased for all composite specimens.