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This study evaluated the high-cycle fatigue strength of AZ91D alloy and AZ91D-5SiC-1Gr (wt.%) hybrid magnesium composite. The samples were produced through the stir casting process, and properties were studied in as-cast and T6 aging heat-treated conditions. Microstructural characterizations, density, porosity, tensile properties, and high-cycle fatigue strength of produced alloy and hybrid composite were evaluated. The maximum obtained ultimate tensile strength, yield strength (0.2%), and ductility for T6-heat-treated hybrid composite were 176, 56.5 MPa, and 8.1%, respectively, and density of 1.855 g/cc. Stress-controlled, fully reversed high-cycle fatigue test was performed on the samples subjected to axial load and rotary bending load fatigue test. Fatigue results indicated that produced hybrid composite possessed higher cycle fatigue strength than the parent AZ91D alloy. AZ91D-5SiC-1Gr (wt.%) (T6) sample reported 55,434 cycles to failure at 28.25 MPa stress amplitude which is 4.33 times higher than as-cast AZ91D alloy. Maximum rotary bending load fatigue life of 101,916 cycles was obtained for T6-hybrid composite samples at 18.2 MPa stress amplitude. The reliability of fatigue strength has been studied through the R–S–N method, and results indicate that the fatigue life of the T6-hybrid composite possesses 81,377 cycles at 99% reliability and 98,627 cycles at 50% reliability. Hence, the addition of SiC and graphite and aging heat treatment at 100 °C enhances the tensile and fatigue strength of the parent AZ91D alloy. [ABSTRACT FROM AUTHOR]

This paper focuses on the effect of yarn diameter, the density of yarn, woven type, Gram per Square Metre (GSM) and weight fraction fibre on tensile, flexural and impact properties of weaved sisal composite. Various types of woven fabrics were prepared from sisal fibres, and these fabrics are used to prepare the composites of variable weight fraction (Wff) as 20, 40, 50 and 60 percent by maintaining proper alignment of warp and weft direction. The tensile, flexural, and impact properties were found to increase with Wff content in all types of woven pattern composites. Plain 1 (P1) shows better mechanical properties as compared to Plain 2 (P2) and Plain 3 (P3)-based composites, and this shows GSM has a higher significance on mechanical properties. Further, the influence of woven pattern was analysed and found that the plain woven exhibits better tensile strength, but the herringbone exhibits better flexural and impact strength. Scanning Electron Microscope evidenced that good interfacial bonding between fibre and matrix interface. [ABSTRACT FROM AUTHOR]

The Al-7075 aluminium alloy has been proposed for widespread use in automotive applications. This material has been researched in composite structures with various reinforcements in order to improve its usage. In this study, Fe3O4 (magnetite) is reinforced in an Al-7075 matrix to create a metal matrix composite by a stir casting process. Aside from the Neat Matrix samples, five samples were produced by adding Fe3O4 to Al 7075 matrix in various weight proportions such as 2, 4, 6, 8, and 10. The mechanical properties of the fabricated composite specimens were determined by different tests, including hardness, tensile, compression, and wear strength. The results were compared to a standard matrix alloy. In addition, SEM with EDAX studies was performed to examine the dispersion of the reinforced particles in the chosen matrix alloy. The homogeneous distribution of Fe3O4 particles in composites was observed to be intragranular in origin. Furthermore, Fe3O4 particles were found to be well attached to the matrix alloy, with a clean interface. The composite's hardness and tensile strength along with wear resistance were also found to increase as the Fe3O4 concentration increased. [ABSTRACT FROM AUTHOR]

Polymeric materials reinforced with synthetic fibres such as glass, carbon, and aramid provide advantages of high stiffness and strength to weight ratio as compared to conventional construction materials, i.e., wood, concrete, and steel. Despite these advantages, the widespread use of synthetic fibre-reinforced polymer composite tends to decline because of their high-initial costs, their use in non-efficient structural forms, and, most importantly, their adverse environmental impact. The banana fibres were chemically modified through contact with 10 wt % sodium hydroxide solutions for 45 minutes. Polymeric composites with different fibre lengths were prepared through the hand lay-up process at room temperature. Prepared composites exhibited better mechanical and thermal properties. The tensile strength increased with an increasing fibre length of the banana fibre in epoxy matrix composites, due to the stronger interfacial interactions between the treated fibres and the epoxy matrix. These effects occurred due to the morphological and chemical changes in the treated fibre surfaces, which promote better adhesion between the fibres and the epoxy matrix. [ABSTRACT FROM AUTHOR]

Spark plasma sintering of Al-Cu composites yields a refined low segregation microstructure and the conversion of spherical grains to irregular non-dendritic structures during the cooling phase of the process. Al-4.5Cu alloy powder with an average particle size of 210 to 250 µm was gas atomised in an inert gas for physical and mechanical characterisations. The alloy powder was compacted into cylindrical specimens of 30 mm diameter and 20 mm thickness. The Al-4.5 wt. % Cu alloy powder was filled in enclosed graphite die and with the application of pressure and heat, the sintering samples were developed. For microstructural characterisation and mechanical properties, test samples were prepared by using Electrical discharge machining wire-cutting machine according to ASTM standards. The density of the alloy was improved in the range of 4.7% to 7.8% and the hardness value was improved by more than 100% when compared to the conventionally sintered Al-4.5Cu alloy. The compressive strength of the spark plasma sintered alloy is much higher than the conventionally sintered alloy samples by 307.32%, 150.15% and 47.45%. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate at the mechanical characteristics of Fe3O4 particle reinforced with 7075 aluminium alloy composite. The composites of different weight percentage 2%, 4%, 6%, and 8% of Fe3O4 reinforcement were prepared using stir casting technique. Prepared composite samples were examined for mechanical properties like tensile percentage elongation and hardness test along with scanning electron microscopy. Additionally, corrosion was also conducted on the prepared samples. The results of mechanical properties reveal that improvement in hardness and tensile strength and corrosion resistance values with different weight percentage combinations. When compared to the original Al7075 alloy, the Ultimate Tensile Strength is highest at a value of 64.563% for 8% Fe3O4 reinforcement, and variation in Ultimate Tensile Strength is highest at a value of 21.865% for an increase in reinforcement percentage from 4% to 6% weight, according to the experimental studies.. [ABSTRACT FROM AUTHOR]

In this study, fracture toughness test of short banana fibre-reinforced epoxy composites was carried out. The main interest of this study is to incorporate environmentally friendly biodegradable banana fibres in polymer composites to prove the potential of natural fibres. The short fibres from pseudo-stem part of the banana plant were used to prepare composites. The composite samples were prepared using both alkali-treated and untreated banana fibres. Laminates were prepared from vacuum moulding technique. The effects of alkali-treated fibres on untreated were studied. Since polymer composites are used in many structural applications, these materials because of defects which material failure. The better understanding of material behaviour due to crack growth studies on fracture is essential. In this study, banana fibre-reinforced epoxy composites are developed and their mechanical properties such as tensile strength, impact strength and fracture toughness are evaluated. The fibre matrix adhesion and internal surface of the fractured surfaces are studied by using a scanning electron microscope. [ABSTRACT FROM AUTHOR]

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