In the aerospace industry, materials used as modern engine components must be able to withstand extreme operating temperatures, creep, fatigue crack growth and translational movements of parts at high speed. Therefore, the parts produced must be lightweight and have good elevated-temperature strength, fatigue, resistant to chemical degradation, wear and oxidation resistance. High entropy alloys (HEAs) characterize the cutting edge of high-performance materials. These alloys are materials with complex compositions of multiple elements and striking characteristics in contrast to conventional alloys; their high configuration entropy mixing is more stable at elevated temperatures. This attribute allows suitable alloying elements to increase the properties of the materials based on four core effects , which gives tremendous possibilities as potential structural materials in jet engine applications. Researchers fabricate most of these materials using formative manufacturing technologies; arc melting. However, the challenges of heating the elements together have the tendency to form hypoeutectic that separates itself from the rest of the elements and defects reported are introduced during the casting process. Nevertheless, Laser Engineering Net Shaping (LENS™) and Selective Laser Melting (SLM); a powderbased laser additive manufacturing process offers versatility, accuracy in geometry and fabrication of three-dimensional dense structures layer by layer avoiding production errors.

A way to avoid or minimize the side effect that could result in drug delivery to cells with increased efficiency and performance in the health rehabilitation process is to use biocompatible and biodegradable drug carriers. These are essentially biomaterials that are metallic, ceramic, or polymeric in nature. The sources of these materials must be biological in its entire ramification. The classification, synthesis, processing, and the applications to which these materials are put are the essential components of having suitable target cell drug carriers. This chapter will be devoted to discussing biomaterials suitable as drug carrier for use in the health-related matters of rehabilitation.

Purpose This study aims to review the recent advancements in high entropy alloys (HEAs) called high entropy materials, including high entropy superalloys which are current potential alternatives to nickel superalloys for gas turbine applications. Understandings of the laser surface modification techniques of the HEA are discussed whilst future recommendations and remedies to manufacturing challenges via laser are outlined. Design/methodology/approach Materials used for high-pressure gas turbine engine applications must be able to withstand severe environmentally induced degradation, mechanical, thermal loads and general extreme conditions caused by hot corrosive gases, high-temperature oxidation and stress. Over the years, Nickel-based superalloys with elevated temperature rupture and creep resistance, excellent lifetime expectancy and solution strengthening L12 and γ´ precipitate used for turbine engine applications. However, the superalloy’s density, low creep strength, poor thermal conductivity, difficulty in machining and low fatigue resistance demands the innovation of new advanced materials. Findings HEAs is one of the most frequently investigated advanced materials, attributed to their configurational complexity and properties reported to exceed conventional materials. Thus, owing to their characteristic feature of the high entropy effect, several other materials have emerged to become potential solutions for several functional and structural applications in the aerospace industry. In a previous study, research contributions show that defects are associated with conventional manufacturing processes of HEAs; therefore, this study investigates new advances in the laser-based manufacturing and surface modification techniques of HEA. Research limitations/implications The AlxCoCrCuFeNi HEA system, particularly the Al0.5CoCrCuFeNi HEA has been extensively studied, attributed to its mechanical and physical properties exceeding that of pure metals for aerospace turbine engine applications and the advances in the fabrication and surface modification processes of the alloy was outlined to show the latest developments focusing only on laser-based manufacturing processing due to its many advantages. Originality/value It is evident that high entropy materials are a potential innovative alternative to conventional superalloys for turbine engine applications via laser additive manufacturing.

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Aerospace components and their coatings are required to possess excellent surface properties over a wide temperature range. Stainless steels, titanium, nickel superalloy, and more recently high entropy alloys (HEAs) have been used to improve the exterior properties of these components. In this study, AlTiCrFe-CoNi and AlCoCrFeNiCu HEAs were successfully fabricated using laser additive manufacturing to produce coatings on an A301 steel base plate. The influence of the laser parameters (laser power and scan speed) on the microstructure and hardness properties were also investigated. The results revealed that coatings homogeneously adhered to the baseplate. The optimum processing parameters for both alloys with defect-free structures at a preheat temperature of 400 • C, were at 1200-1600 W at 8-12 mm/s with the layers composed of both face centred-cubic (FCC) and body centred-cubic (BCC) phases. The laser parameters affected the quality and hardness properties of the alloys. The results showed that optimizing the laser parameters achieved by preheating temperature invariably improved the performance of the alloys with potential coatings and structural applications.

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Background In recent years, solar photovoltaic technology has experienced significant advances in both materials and systems, leading to improvements in efficiency, cost, and energy storage capacity. These advances have made solar photovoltaic technology a more viable option for renewable energy generation and energy storage. However, intermittent is a major limitation of solar energy, and energy storage systems are the preferred solution to these challenges where electric power generation is applicable. Hence, the type of energy storage system depends on the technology used for electrical generation. Furthermore, the growing need for renewable energy sources and the necessity for long-term energy solutions have fueled research into novel materials for solar photovoltaic systems. Researchers have concentrated on increasing the efficiency of solar cells by creating novel materials that can collect and convert sunlight into power. Main body of the abstract This study provides an overview of the recent research and development of materials for solar photovoltaic devices. The use of renewable energy sources, such as solar power, is becoming increasingly important to address the growing energy demand and mitigate the impact of climate change. Hence, the development of materials with superior properties, such as higher efficiency, lower cost, and improved durability, can significantly enhance the performance of solar panels and enable the creation of new, more efficient photovoltaic devices. This review discusses recent progress in the field of materials for solar photovoltaic devices. The challenges and opportunities associated with these materials are also explored, including scalability, stability, and economic feasibility. Conclusion The development of novel materials for solar photovoltaic devices holds great potential to revolutionize the field of renewable energy. With ongoing research and technological advancements, scientists and engineers have been able to design materials with superior properties such as higher efficiency, lower cost, and improved durability. These materials can be used to enhance the performance of existing solar panels and enable the creation of new, more efficient photovoltaic devices. The adoption of these materials could have significant implications for the transition toward a more sustainable and environmentally friendly energy system. However, there are still challenges to be addressed, such as scalability, stability, potential environmental effects, and economic feasibility, before these materials can be widely implemented. Nonetheless, the progress made in this field is promising and continued reports on the research and development of materials for solar photovoltaic devices are crucial for achieving a sustainable future. The adoption of novel materials in solar photovoltaic devices could lead to a more sustainable and environmentally friendly energy system, but further research and development are needed to overcome current limitations and enable large-scale implementation.

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