Glass Particulate Composites Research Articles

Characterization of Cassava Starch Films Strengthened with Glass Particulate Composite

Characterization of cassava starch films strengthened with glass particulate composite was investigated in this study. Glass particulate starch composites was produced using solution casting process with weight percentage (wt.%) of the reinforcement phase ranging from 0% to 20% at 5wt.% interval. The mechanical and physical properties were determined out by standard methods. Themicrostructural analysis of the produced composites was carried out using scanning electron microscope (SEM). The density of the composites increased as the reinforcement content increases,the water absorption decreased as the reinforcement content increases. The SEM analysis showed good adhesion between the starch matrix and the reinforcement, the hardness of the bio-composites improved generally over the unreinforced starch and the biodegradibility of the thermoplastic polymer (starch) degrades faster when compared with the bio-composites.The development of the bio-composite will contribute to knowledge; helps convert waste to wealth and reduce environmental pollution. The bio-composite produced has light weight and can be used in food packaging applications.

Effect of end chills, reinforcement content and carburization on the hardness of LM25-borosilicate glass particulate composite

Aluminium metal matrix composites (AMCs) are widely employed in aerospace and automobile applications. Thus, they are required to operate reliably under a severe corrosive, high temperature and carbonaceous environments, without undergoing any deterioration in their mechanical properties. The paper is the compilation of the experimental results and analysis carried out to investigate the effect of different end chills, reinforcement content and carburization on the LM25 aluminium alloy reinforced with borosilicate glass powder. The composites are prepared via stir casting route by varying the weight percent (wt.%) of the reinforcement starting from 3 wt.% and going up till 12 wt.% with an increment of 3wt.% in every step. To obtain quality castings, end chills are placed within the sand mould. The specimens drawn from the chill-end of the castings are pack carburized in a muffle furnace for a set duration of time. The hardness of the specimens before and after carburization is recorded. The analysis of the results illustrates that the hardness increases linearly with the increase in the reinforcement content within the matrix from 3 wt.% up to 9 wt.%. It is also evident that the Volumetric Heat Capacities (VHC) of the chill material bears a strong effect not only on the quality of the castings produced but also on the hardness of the AMCs. Carburization leads to carbon deposition on the surface causing a change in the hardness of the specimens.

Development and Property Evaluation of Chilled MMC Prepared with LM25 as Matrix and SiO<sub>2</sub> (Glass) Particulates as Dispersoids

Main objective of the present work is to investigate the effect of dispersiod content and the effect of chill on the mechanical properties of chilled MMC with LM25 as matrix and SiO2 as dispersoid. Investigation is carried out to evaluate Ultimate Tensile Strength (UTS), Fracture toughness, Hardness, and microstructure of chilled aluminum matrix and Glass particulate composite. The glass (SiO2) particles ranging from 30-to100µm were chosen as dispersiod and added, ranging from 3to 12wt% in steps of 3%. The composite was prepared by stir-casting technique and poured into the sand molds incorporated with non-metallic and metallic chills. Test result showed that this MMC was greatly influenced by the dispersiod and chills. Fracture toughness & UTS of the composite are found to depend on the wt% of the dispersiod and chilling medium. It is observed that chill has influenced hardness of the composite. Volumetric heat capacity (VHC) of the chill is found to increase the amount of heat absorbed. Microstructure analysis has reveled uniform distribution of the dispersiod, which results in improved properties of the particulate reinforced metal matrix composite.

Compressive evaluation of homogeneous and graded epoxy-glass particulate composites.

The propagation of stress waves in epoxy-glass particulate composites and graded materials was studied experimentally. Materials tested in this study consisted of an epoxy matrix with various concentrations of spherical glass particles having a mean diameter of 42μm. Plate impact experiments were performed using a gas gun. Embedded within the specimens were manganin stress gauges used to record propagating compressive longitudinal stress waves through the material. High strain rate experiments using a Split Hopkinson Pressure Bar (SHPB) apparatus were also performed to evaluate the dynamic strength of the specimens, while quasi-static compression tests were undertaken to characterize their quasi-static behavior. Ultrasonic wave speed measurements were carried-out in order to obtain additional material properties and characterize the gradation in functionally graded materials (FGM). It was found that low volume fractions of particles are detrimental to the performance of the material under impact loading, while concentrations in the range of about 30 to 45% by volume exhibit characteristics of higher degrees of scattering. This suggests that materials in this latter range would be more effective in the thwarting of destructive shock waves than the homogeneous matrix material. Impact testing of FGM specimens suggests that impact loading on the stiff (high volume fraction) face results in much higher levels of scattering. Therefore, such materials would be effective for use in light weight armor or as shielding materials due to their effective attenuation of mechanical impulses.

The effect of low energy impact on the tensile strength of coated and uncoated glass particulate composites

The residual tensile strength of glass filled particulate composites has been determined after low energy impact for various energy values. The material systems constructed for the needs of this research consisted of epoxy resin filled with glass beads. The glass beads were either uncoated or alternatively coated with a reactive silane based bonding agent. Specimens with various filler volume fractions were available. The effect of silane coating as well as the filler volume fraction was analytically discussed. Finally, a model developed in previous work for continuous fibre reinforced composite laminates was adopted to describe the residual tensile strength after impact. In most of the cases the predicted curves fit the experimental results very well.

Wear behavior of chilled (metallic and non-metallic) aluminum alloy–glass particulate composite

The present investigation aims at producing cast aluminum alloy–glass particulate composites in moulds containing metallic and non-metallic chills by dispersing glass particles in a molten aluminum alloy above the liquidus temperature, the size of the particles dispersed being between 20 and 50 μm. The dispersoid being added ranged from 3 to 9 vol.% in steps of 3 vol.%. The resulting composites cast using chills were tested for their wear behavior. Results of the investigation indicate that: (1) the wear resistance of chilled Al–glass composites were remarkably improved by adding glass particles. The effect of the amount of glass content up to 3 vol.% can be ignored until the sliding speed of 0.52 m/s. (2) From the SEM structure studies, wear surfaces of 6 vol.% glass composite, chilled using copper chill at low sliding speed, showed a slight groove formation more than those of the matrix alloy. (3) The strength and wear resistance of the composite developed is highly dependent on the location of the casting, from where the test specimens are taken, and also on the dispersoid content of the composite. (4) Chill thickness and chill material, however, do significantly affect the strength and wear resistance of the composite.

Fabrication and mechanical properties (strength and fracture toughness) of chilled aluminum alloy–glass particulate composite

This paper describes the results obtained and deductions made from a series of strength and fracture toughness tests performed on chilled Aluminum–Glass particulate composite containing dispersoid (size 20–50 μm) content ranging from 3 to 12 wt.% in steps of 3%. The resulting composites cast in moulds at room temperature containing metallic (copper, steel, cast iron) and non-metallic (silicon carbide) chills. The effect of strength and fracture toughness for varying chilling rate and dispersoid content was also examined. The strength and fracture toughness tests were carried out in conformance with AFS (American Foundrymen Society) and ASTM (E 399 1990) standards. Results of the investigation reveal that there is good bonding with consistency in the matrix and as the glass content is increased, the strength and fracture toughness increase remarkably and is highly dependent on the location of the casting from where the test specimens are taken. Large particles and the regions of clusters of particles were found to be the locations prone to damage the composite prior to final fracture.

Tear resistance of short glass fibre and glass particulate hybrid composites

Tear energy and resistance decrease with increase in reinforcement in the case of both short glass fibres and glass particulate composites, but these properties increase with increase in reinforcement of glass particulate and short glass fibre hybrid composites. The mechanical interaction between two types of reinforcement leads to a positive hybrid effect to achieve better tear characteristics.