Search results

This paper aims to produce hybrid reinforcement for the development of aluminium matrix composites using ball-billing technique to avoid or reduce the problem of agglomeration of the reinforcement during casting.

In the present investigation, a mixture of silicon carbide (SiC) and rice husk ash (RHA) powder in equal weight percentage ratio 4:4 (1:1) was alloyed mechanically in a ball-mill at distinct milling times of 15, 30, 45, 60 and 75 h. Morphological Characterization and density measurements of the ball-milled powder were carried out after different intervals of milling times.

The results revealed that the process of ball milling is a novel technique for the conversion of two or more powders in to an integer powder and reduces the problem of agglomeration also. The density measurement results revealed that an increasing trend of density initially and reduction of the density with the increase of milling time. The density value of the combined particles became comparable to the density of aluminium at the milling time of 75 h for the equal weight percentage ratio 4:4 (1:1) of SiC and RHA.

The manuscript highlights the research work related to the development of the reinforcement for the aluminium hybrid composites by ball milling process. The use of this process for the development of the reinforcement not only reduces the problem of the agglomeration but reduces the density mismatch of the reinforcement and matrix material also.

Aluminium metal matrix composite (AMMC) is most popular in various industrial applications such as aerospace, automobile, marine, sports and many others. In common practice, silicon carbide, aluminum oxides, magnesium oxide, graphene and carbon nano tubes are the major reinforcing elements to prepare the AMMC. The purpose of this paper is to develop AMMCs reinforce with eggshell (ES) and rice husk ash (RHA).

Stir casting process is used for preparation of AMMC. From past few years, more emphasis is given to prepare the AMMCs using agro waste such as rice husk and/or ES as reinforcing materials. In this method, after the Al-matrix material is melted; it is stirred vigorously to form vortex at the surface of the melt, and the reinforcement material is then introduced at the side of the vortex. Stir casting process is a vortex and vigorous method to prepare the AMMCs. First, aluminum alloy (AA3105) is melted in the furnace when metal is in semisolid form. Reinforcement, i.e. ES and RHA are preheated at temperature 220°C and 260°C, respectively.

The result of AMMC shows that the tensile strength and hardness increased by using 22.41% and 45.5%, respectively, at 4.75 Wt.% each reinforcement, i.e. ES and RHA, and 1% Cr. The toughness and ductility of metal matrix composite (MMCs) have decreased up to 23.31% and 19.23% respectively by using 1% Cr, 4.75 wt. % ES and by 4.75 wt. % RHA of composite material.

In this work, Cr, waste ES and RHA have been used to develop green MMC to support the green revolution as promoted/suggested by United Nations, thus reducing the environmental pollution.

The purpose of this paper is to determine the use of BLA along with SiC as economical reinforcements to enhance the mechanical behavior of hybrid composite. The purpose of this research is the development of cost-effective aluminum hybrid metal matrix composites.

The present research work investigation evaluated the mechanical properties of Al-4.5%Cu alloy, Al-4.5Cu/10SiC, Al-4.5Cu/10SiC/2BLA and Al-4.5Cu/10SiC/4BLA composites by the Stir casting method. The fabricated composites were analyzed using optical microscopy (OM), scanning electron microscopy (SEM), and hardness and tensile test.

The microstructure modification with the addition of reinforcement particles in the matrix alloy and clear interface in between matrix and particles are observed. The density of the composite increased with the addition of SiC and decreased with the addition of BLA in comparison with that of matrix alloy. The hardness and tensile strength of the single-reinforced composite and hybrid composites improved with the addition of reinforcement particles. The strengthening of composites was due to load-bearing capacity of reinforcement particles over the matrix alloy and increased dislocation density of composites materials. The tensile failure mechanism of the composites is reveled with SEM analysis.

The papers reports the development of cost-effective and light weight aluminum hybrid composites with remarkable enhancement in the mechanical and tribological properties with the addition of BLA as economical reinforcement along with SiC.

The density, hardness and tensile values of fabricated aluminium composites were presented in this paper for the use in the engineering applications where the weight and cost are consider as a primary factors.

The purpose of this paper is to study Al-based green composite. To make composite samples of aluminium alloy (AA3105) with different weight percentages of rice husk ash (RHA) and eggshell (ES) particles as reinforcement, stir casting method was used.

Several other aspects, including the weight percent of reinforcing agent particles, the applied stress and the sliding speed, were taken into consideration. During the course of the wear test, the sliding distance that was recorded varied from a minimum of 1,000 m all the way up to a maximum of 3,135 m (10, 15, 20, 25 and 30 min). The typical range for normal loads is 8–24 N, and their speed is 1.58 m/s.

With the AA/ES/RHA composite, the wear rates decreases when the grain size of the reinforcing particles enhanced. Scanning electron microscopy images of worn surfaces show that at low speeds, delaminating and ploughing are the main causes of wear. At high speeds, ploughing is major cause of wear. Composites with better wear-resistant properties can be used in wide range of tribological applications, especially in the automotive industry. It was found that hardness increases at the same time as the weight of the reinforcement increases. Tensile and hardness were maximized at 10% reinforcement mix in Al3105.

In this work, ES and RHA has been used to develop green metal matrix composite to support green revolution as promoted/suggested by United Nations thus reducing the environmental pollution.

This study aims to attempt to make an aluminum-based composite using reinforcement such as graphite and fly ash. Pollution is an enhanced serious issue of concern for global. Industries play a major role in disturbing the balance of the environment system. Composite is made by using the stir casting technique. The waste that is generated by the industries if left untreated or left to be rotten at some place may prove fatal to invite various types of diseases. Proper treatment of these wastes is the need of the hour, the best way to get rid of such kinds of hazardous wastes is to use them by recycling.

Stir casting technique was used to make a composite. Graphite and fly ash were mixed with equal amounts of 2.5% to 15% in aluminum. The microstructure of composite formed after composite was noticed. After seeing the microstructure it was understood that reinforcement particles are very well-mixed in aluminum.

When graphite was mixed with 3.75% and 3.75% fly ash in aluminum, the strength of the composite came to about 171.12 MPa. As a result, the strength of the composite increased by about 16.10% with respect to the base material. In the same way, when 3.75% graphite and 3.75% fly ash were added to aluminum, the hardness of the composite increased by about 26.60%.

In this work, graphite and fly ash have been used to develop green metal matrix composite to support the green revolution as promoted/suggested by United Nations, thus reducing the environmental pollution. The addition of graphite and fly ash to aluminum reduced toughness. The thermal expansion of the composite has also been observed to know whether the composite made is worth using in higher temperatures.

The quantum of metal particle waste generation in manufacturing industries is posing a great concern for the environment. The iron forging industries generate a huge amount of grinding sludge (GS) waste, which is disposed into the earth. The accumulation of this waste in dump yards causes an increase in soil and air pollution levels.

In the current investigation, an effort was made to use this waste GS for the progress of aluminum-based composite. To maintain uniform distribution of reinforcing material, the friction stir processing technique was used.

The characterization based on the SEM image of the Al/GS composite revealed that uniform dispersal of reinforcement content can be attained in a single tool pass. Number of grains/inch was approximately 2,402. XRD of GS powder confirmed the presence of SiO₂, Fe₂O₃, Al₂O₃ and CaO phases. These phases proved GS to be a better reinforcement with aluminum alloy. Tensile strength and hardness were significantly improved in comparison to the aluminum alloy. Thermal expansion and corrosion weight loss were evaluated to observe the influence of GS addition.

The studies proved that the use of GS as reinforcement material can help in curbing the menace of soil pollution to a large extent.

The purpose of this paper is to determine the factors influencing adoption of African indigenous vegetables (AIVs) into the agro-pastoral farming systems aiming at improving livelihoods.

The paper is based upon the diffusion theory which is linked to the random utility theory. A survey of 205 agro-pastoral households obtained through multistage sampling technique was used. Factors influencing adoption of AIVs were estimated using a logit model.

Findings indicate that the acreage under AIVs was still very low compared to other crop enterprises with the most common types of AIVs grown being Solanum nigrum, Amaranthus spp., Cucurbita maxima, Vigna unguiculata, Basella alba and Cleome gynandra. Factors influencing adoption were found to be gender, age, farm size, education level, off-farm income and number of visits to extension officer.

Limitations include reliance on respondents’ willingness to provide correct information.

This paper adds value in its contribution to literature on diversifying agro-pastoral livelihoods through production of AIVs for income and food security.

This study aims to minimize pollution and enhance the mechanical properties of SiC- reinforced aluminum- based composite by utilizing waste eggshell. Pollution is increasing at an exponential rate across the globe. Every nation is struggling to have strong control over the rise in pollution. Many countries are even successful in this regard, but only up to a certain extent; also, a lot of capital investment is required just to make arrangements for making and taking care of dedicated dump yards. An alternative approach in this regard could be using the unwanted wastes in some constructive works by recycling them. Novel strategies and dedicated cells for the research and development regarding the recycling of various kinds of wastes are continuously being developed by various nations.

This study attempts to make a hybrid composite of AA6101 alloy through the friction stir process (FSP) technique in which waste eggshells and SiC have been used as reinforcement particles. As the densities of eggshells, SiC show different values of densities to make them a single entity, they were subjected to ball milling for around 75 h. After ball milling, the reinforcement particles (eggshells and SiC) were distributed uniformly in the metal matrix (Al), and they appear as a single entity in the metal matrix composite.

The main objective of this study is to obtain an enhanced value of tensile strength of the final composite. Concerning this, the parameters of FSP, i.e. rotational speed and transverse speed, have been optimized through the Box–Behnken design approach. The optimized values of FSP parameters came out to be as 935.92 rpm of rotational speed and 22.48 mm/min as transverse speed value.

The results showed that the tensile strength and hardness of the composite developed at an optimum combination of FSP parameters enhanced by about 47.14 and 45.45%, respectively.

This paper aims to explore the intellectual structure shaping the circular economy (CE) discourse within the built environment in Africa.

The study adopted a bibliometric analysis approach to explore the intellectual structure of CE in the built environment in Africa. The authors collected 31 papers published between 2005 and 2021 from the Scopus database and used VOSviewer for data analysis.

The findings show that there are six clusters shaping the intellectual structure: demolition, material recovery and reuse; waste as a resource; cellulose and agro-based materials; resilience and low-carbon footprint; recycling materials; and the fourth industrial revolution. The two most cited scholars had three publications each, while the top journal was Resources, Conservation and Recycling. The dominant concepts included CE, sustainability, alternative materials, waste management, lifecycle, demolition and climate change. The study concludes that there is low CE research output in Africa, which implies that the concept is either novel or facing resistance.

The data were drawn from one database, Scopus; hence, adoption of alternative databases such as Web of Science, Google Scholar and Dimensions could potentially have yielded a higher number of articles for analysis which potentially would result in different conclusions on the subject understudy.

This study made a significant contribution by articulating the CE intellectual structure in the built environment, identified prominent scholars and academic platforms responsible for promoting circularity in Africa.

Examines the tenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.