A comprehensive review of techniques for natural fibers as reinforcement in composites: Preparation, processing and characterization.

The increase in awareness of the damage caused by synthetic materials on the environment has led to the development of eco-friendly materials. The researchers have shown a lot of interest in developing such materials which can replace the synthetic materials. As a result, there is an increase in demand for commercial use of the natural fiber-based composites in recent years for various industrial sectors. Natural fibers are sustainable materials which are easily available in nature and have advantages like low-cost, lightweight, renewability, biodegradability and high specific properties. The sustainability of the natural fiber-based composite materials has led to upsurge its applications in various manufacturing sectors. In this paper, we have reviewed the different sources of natural fibers, their properties, modification of natural fibers, the effect of treatments on natural fibers, etc. We also summarize the major applications of natural fibers and their effective use as reinforcement for polymer composite materials.

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Natural Fibers as Sustainable and Renewable Resource for Development of Eco-friendly Composites: A Comprehensive Review

Renewable and sustainable biobased materials: An assessment on biofibers, biofilms, biopolymers and biocomposites

There has been much effort to provide eco-friendly and biodegradable materials for the next generation of composite products owing to global environmental concerns and increased awareness of renewable green resources. An increase in the use of natural materials in composites has led to a reduction in greenhouse gas emissions and carbon footprint of composites. In addition to the benefits obtained from green materials, there are some challenges in working with them, such as poor compatibility between the reinforcing natural fiber and matrix and the relatively high moisture absorption of natural fibers. Green composites can be a suitable alternative for petroleum-based materials. However, before this can be accomplished, there are a number of issues that need to be addressed, including poor interfacial adhesion between the matrix and natural fibers, moisture absorption, poor fire resistance, low impact strength, and low durability. Several researchers have studied the properties of natural fiber composites. These investigations have resulted in the development of several procedures for modifying natural fibers and resins. To address the increasing demand to use eco-friendly materials in different applications, an up-do-date review on natural fiber and resin types and sources, modification and processing techniques, physical and mechanical behaviors, applications, life-cycle assessment, and other properties of green composites is required to provide a better understanding of the behavior of green composites. This paper presents such a review based on 322 studies published since 1978.

A review of natural fiber composites: properties, modification and processing techniques, characterization, applications

Friction stir welding/processing of metals and alloys: A comprehensive review on microstructural evolution

In the present investigation friction stir processing (FSP) is carried out by single and multipass FSP on a 5086 aluminum alloy to modify microstructure and mechanical properties. The processing is carried out at constant rotation speed of 1025 rpm and at a traverse speed of 30 mm/min. Inhomogeneous microstructural distribution was observed across the processed zone. EBSD analysis has been done to evaluate the microstructure. Overlapping passes is showing same grain size as in single pass FSPed material. Material processed using multi pass FSP at 30 mm/min is showing higher mechanical strength as compared to base material. The bulk material produced due to multipass seems to be good for superplastic forming applications.

Microstructural and Mechanical Characterization of Friction Stir Processed 5086 Aluminum Alloy

Al7075 alloy reinforced with h-Boron Nitrate (BN) composites were processed by stir casting technique. The produced composite was subjected to microstructural studies using OLYMPUS -BX51M, tensile, hardness, density and wear tests. Tensile strength and hardness were found to increase by 12.8% and 20% respectively due to increased dislocation density with the addition of reinforcement. Microstructure showed grain refinement with reinforcement addition and reinforcement acts as nucleating sites with an approximately uniform distribution of reinforcements. Wear test was conducted with different loads 10, 20 and 30N for a sliding distance of 1500 m. Wear mass loss of composites showed improved wear resistance with variation in reinforcements. Worn surfaces were examined using SEM, which showed the presence of delamination, plough and debris on the surface. Due to the addition of low-density h-BN, the density of composites decreases with increase in reinforcement content.

https://www.ije.ir/article_87120_bc332b63d26ac0b75d3d33bc648acf83.pdf

Effect of Hexagonal Boron Nitrate on Microstructure and Mechanical Behavior of Al7075 Metal Matrix Composite Producing by Stir Casting Technique

The objective of this study was to examine the prevalence of neck pain and to explore its association with individual job and demographical risk factors among hand screen printing workers. These factors include gender, age, marital status, smoking and drinking habits, willingness of the workers, sick leave, working efficiency and experience. A questionnaire survey was taken among the 385 working labours with different age groups in the western part of Tamil Nadu. The result shows that the prevalence of neck pain among the workers of the hand screen printing was about 27.8%. The female workers, higher age group workers, married workers and higher experienced workers seem to have a higher MSD and discomfort. This study statistically illustrates the effect of job and demographic factors on neck pain among hand screen printing workers.

Association of Job and Demographical Risk Factor with Occurrence of Neck Pain Among Hand Screen Printing Workers

Characterization of raw and alkali treated prosopis juliflora fibers for potential polymer composite reinforcement

In the present work, 5086 Al alloy is subjected to single and multi pass friction stir processing (FSP) to modify microstructure and mechanical anisotropy. The processing is carried out at constant rotation speed of 1025 rpm and different traverse speeds of 30 mm/min and 50 mm/min with and without cooling. Mechanical anisotropy is evaluated in terms of normal and planar anisotropy by performing tensile test in 0, 45 and 90o direction to processing direction. Material processed using multi pass FSP at 30 mm/min is showing lower planar anisotropy as compared to base material. The mechanical anisotropy property is correlated with the development of micro texture.

S. Pradeep

Papers

Microstructural and Mechanical Characterization of Friction Stir Processed 5086 Aluminum Alloy

Effect of Hexagonal Boron Nitrate on Microstructure and Mechanical Behavior of Al7075 Metal Matrix Composite Producing by Stir Casting Technique

Association of Job and Demographical Risk Factor with Occurrence of Neck Pain Among Hand Screen Printing Workers

Characterization of raw and alkali treated prosopis juliflora fibers for potential polymer composite reinforcement

Influence of Friction Stir Processing Parameters on Anisotropic Behavior Property of 5086-O Aluminum Alloy