60 research outputs found
Surface composites and functionalisation : enhancement of aluminium alloy 7075-T651 via friction stir processing
Get PDFAbstract: This research work is aimed at modifying and enhancing the properties of aluminium alloy 7075- T651 through the friction stir processing (FSP) technique, in order to improve the mechanical, electrochemical, structural, tribological as well as the metallurgical properties which include micro- and macro- structural analysis through XRD and Image processing of grain size and grain flow patterns determination, by reinforcing the parent metal. The surface modification of the parent metal has been made possible in the past via different techniques,such as laser surfacing, electronbeam welding and thermal spraying; but in recent years, the friction stir processing (FSP) technology has been adopted to cater for the complex methods of surface enhancement. FSP is well-renowned for its short route of fabrication, densification, grain refinement, homogenization of the precipitates of composite substances, nugget zone homogeneity. These have led to the efficient surface enhancement, significant and remarkable improvement in hardness, ductility, strength, increased fatigue life, as well as formability within which the bulk properties are still intact. The use of FSP in the fabrication of metal matrix composites (MMCs), especially aluminium matrix composites (AMCs) and aluminium hybrid composites (AHCs) were dealt with in this study...Ph.D. (Mechanical Engineering
Piezoelectric effects on bone modeling for enhanced sustainability
Get PDF© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)Bone tissue possesses piezoelectric properties, allowing mechanical forces to be converted into electrical potentials. Piezoelectricity has been demonstrated to play a crucial role in bone remodelling and adaptability. Bone remodelling models that consider strain adaptation, both with and without piezoelectric effects, were simulated and validated in this study. This simulation help to better comprehend the interplay between mechanical and electrical stimulations during these processes. This study aimed to optimise the modelling of piezoelectric effects in bone modelling analysis. The connection between mechanical loads applied to bones and the resulting electrical charges generated by the piezoelectric effect was examined. Furthermore, mathematical modelling and simulation techniques were employed to enhance the piezoelectric effect and promote bone tissue growth and repair. The findings from this research have substantial implications for developing novel therapies for bone-related diseases and injuries. It was observed that electrically stimulated bone surfaces increased bone deposition. In some instances of physical disability or osteoporosis, therapeutic electrical stimulation can supplement the mechanical stresses of regular exercise to prevent bone loss. Consequently, the bone remodelling method on the software platform enables easy application and repetition of finite element analysis. This study significantly benefits bone tissue/biomedical engineering, particularly in bone remodelling, healing, and repair.Peer reviewe
Review on thermal, thermo-mechanical and thermal stress distribution during friction stir welding
Get PDFAbstract: Thermal has significant effects on the metal structure during welding process; it plays vital roles in rearranging molecular structure of the metal being welded. It is of great importance to have the knowledge of thermal, temperature, thermo-mechanical and heat distribution on the workpiece in friction stir welding as this will help in designing process and the model parameters for welding application in the following welded joints, edge butt, lap, square butt, T lap, fillet, multiple lap etc. The physics of heat generation must be explored in order to understand the workability of friction stir welding (FSW). The FSW process begun with initial friction of mechanical that took place between the tool and the welded surface resulting in the generation of heat. Since the discovery of Friction Stir Welding (FSW) in 1991, many researchers have done tremendous investigations into the process and many experimental, theoretical, numerical, empirical, computational and analytical methods have been carried out in order to analyse and optimize FSW and to understand the complex mechanism in friction stir welding at the same time to deal with effects of various parameters relating to thermal profile during the process of FSW
Improvement of ASTM A53 Steel Durability Using Agrowastes as Carburizing Agent
Get PDF The importance of steel in manufacturing and construction over the past century cannot be over-emphasized and easy accessibility couple with excellent mechanical properties make it preferable over others. However, the problem of durability has posed a serious concern as majority of steel application are meant for long term use. Several attempts have been made to improve the durability of steel in the past and increase of carbon content in low carbon steel was found to be a suitable agent. Although getting carbon is not the challenge rather obtaining it from a sustainable source that has zero environment impact. This research identified two separate agro-waste that has high carbon content the issue of sustainability brought about the development of carburizing agent from agro-waste that are easily accessible namely palm kernel and eggshell which is employed in this research. The use of agro-waste was found to be effective as there was notable increase in grain structure of the carburized steel when compared to the control sample without carburized agent in it
Composition, characteristics and socioeconomic benefits of palm kernel shell exploitation - an overview
Get PDFAbstract: Intensive research has increased the creation of new biomaterials with specific engineered properties. It is on record that a large amount of these biomaterials waste are generated by the processing of palm oil that invariably causes an environmental problem. This review study sheds light on various applications that palm kernel shell (PKS) has been used for in the recent years and applications that could also be considered in the near future. It has been reported that tropical belt of Africa, Asia and Brazil are the highest producers and exporters of palm oil across the globe and by implication the most producers of the PKS. The PKS as a biomaterial waste product got after the processing of palm oil has been extensively utilized in the various form of applications for both technical and environmental benefits varying from additive, energy production, reinforcement, aggregation, water purification and as well as a composite matrix. It was observed that great use of this waste product is prominent in the structural components, automotive parts as well as water detoxifier. The PKS-powder has been characterized in this review through the use of Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis. The milling was done with the aid of digital Vibratory disc milling machine for 0, 10, 15 and 20 min. Zero min was taken to be when it was sieved with a 300 μm ASTM standard sieve. It was established in the study that the duration of the milling affects volume, surface area, particle size, pore size distributions, micro structure and some other mechanical properties as well as the morphology of the powder. The particles size got reduced from 300 μm to average diameter of 200 nm. The variations in elemental compositions of palm kernel shell powder from as they were affected by milling. The micrographs revealed that there was a tremendous reduction in grain size from 300 μm to about 200 nm
Shape memory polymer review for flexible artificial intelligence materials of biomedical
Get PDFThe self-healing and biocompatibility of polymer composites for biomedicine have made them a preferred approach for small-scale tissue engineering elements. By moving from static to dynamic pressure, 4D printing simulates the natural physical-mechanical changes of living tissue over time. A promising new platform with excellent controllability actuation is required to enhance the significance of 4D printing for biological applications. This study systematically analyses current 4D printing technologies for the flexible fabrication of artificial intelligence (AIM) materials. In addition, many potential applications of flexible 4D printing in composite biological engineering are thoroughly investigated. We found that knowledge about this new category of flexible AIM composites is relatively limited, and the potential for practical applications has not yet been demonstrated. Finally, we discuss the problems and limitations of flexible 4D printing technology, AIM, and future approaches and applications.</p
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