Search

The transportation industry is one of the greatest contributors to a growing carbon footprint. As the world increasingly prioritizes a greener and cleaner future, the transition from ICEs to EVS offers significant benefits as EVs are zero-emission vehicles. However, considering the production and disposal stages of EVs, they cannot be considered entirely emission-free. But in comparison to ICEs, they still have a much smaller carbon footprint. Moreover, studying EV technology is essential to bringing this to the lowest possible extent. However, these advancements come with challenges. In this review article, we have taken an in-depth look into the various challenges, namely the economic challenges, technological challenges, and environmental challenges, faced by EV technology today and the various solutions proposed by researchers, their limitations, and future potential in EV technology advancement. Within this context, we discuss the influence of governmental policies, accessibility and affordability of EVs to the masses, natural and man-made disasters, economic instability, technological limitations posed by the vehicle technology, and limitations posed by battery technology with batteries being the central element for EVs, limitations associated with the existing infrastructure and its ability to support widescale use of EVs, and environmental factors like carbon footprint, among other factors, on EVs technology and the opportunities this technology can make use of in the future. This paper discusses these concerns in detail and gives extensive insight into the challenges, solutions, and future trends pertaining to economic impacts, vehicle technology, battery technology, power grids and charging infrastructure, and environmental impact, of EVs and EV technology.

In harsh working environments where there can be very high temperatures and heavy loads, like in the inside of the combustion chamber of a rocket, industrial gas turbines, space vehicles, and so on, a special class of material will be needed for making the required parts. This special class of materials is called superalloys. There are many types of superalloys based on the major alloying element. But, among these, Ni-superalloys stand out significantly due to their superior mechanical and physical characteristics. Thus, they are widely used in situations where the working conditions are unbearably harsh for ordinary materials. And, due to this, a lot of research have been done on Ni-superalloys for improving them and studying their properties. This extensive research work has led to the development of many generations of Ni-superalloys, with alloys getting better and better with each passing generation. Among all generations, the 5th and 6th generations of Ni-superalloys are the most recently developed ones. With the development of 5th and 6th gen alloys being very recent, there are not many studies conducted on them. With the current bloom in aerospace, energy, and thermonuclear research fields, the need for materials such as Ni-superalloys that can withstand absurdly harsh environments is increasing. That is one of the reasons why reviewing existing studies pertaining to recently developed new generation alloys is very important. It can help us in finding out the future possibilities for research so that we can develop new alloys or improve the existing ones. In this review paper, various aspects of these alloys such as fatigue properties, creep properties, oxidation resistance properties, corrosion resistance properties, element composition of these alloys and their impact on the above factors, use of various manufacturing methods, and the presence of additives have been extensively studied.

This paper discusses the permeation characteristics of concrete made by increasing the fineness of the conventional mineral admixtures and using them as a partial substitute for cement. Silica fume and metakaolin ground to ultrafine state and ceramic powder obtained from grinding waste ceramic tiles were used as mineral admixtures. The mixes were designed for a compressive strength of 50 MPa and were prepared for both binary and ternary blended cases. Binary blended specimens were cast, partially replacing cement with unground silica fume, ground silica fume, unground metakaolin, and ground metakaolin separately in different replacement proportions. Ternary blended mixes were prepared using ceramic powder in 4%, 9%, and 14% and with silica fume in a constant level of 1% percentage. All the cast specimens were compared against the control concrete. A deeper comparative analysis was also made by comparing the performance of specimens made with unground mineral admixtures with that of ground mineral admixtures. Various parameters such as resistance against water absorption, percentage of voids, and sorptivity characteristics were studied. It was observed that increasing the fineness helps fill up the pores, thereby improving the resistance to permeation action.

In this review article, research papers related to recent developments in Ni-superalloy technologies have been reviewed in order to provide an insight into recent achievements and the potential for further study, research, and development in this field. In this paper, studies on various aspects of Ni-based superalloys are reviewed, such as production methods, which include widely used casting methods, as well as unconventional alternative procedures, novel techniques, or simulation and prediction of certain alloy casting properties. Reviewing was done by categorising the papers into 4 major categories: manufacturing of Ni-based superalloys, effects of alloying elements, physical and mechanical properties of Ni-based superalloys, and defects in Ni-based superalloys. The process used to make Ni-superalloy parts can have a huge impact on the production process efficiency, the final product’s quality and properties, and the defects formed in it. Investment casting is one of the most common methods for making Ni-superalloy parts. Manufacturing covers studies on various casting methods used to make Ni-based superalloy components, novel techniques and methods developed to improve casting procedures to produce better products, and alternative manufacturing methods like AM and HIP processing. Similar to production process, the role of alloying elements is also very important. Even minor changes in their compositions can cause significant changes in the final product. Simultaneously, these alloying elements appear to be more efficient in the development of new methods to control product quality, suppress defect formation, and improve material properties such as the creep and fatigue. As a result, the effects of various alloying elements used in castings of Ni-based superalloys are thoroughly examined. A material’s properties are its most important components. They assist the industrialist in selecting or developing a material based on the needs of the application/use. With this in mind, many researchers have conducted extensive research on physical and mechanical properties, as well as how to improve them. Fatigue life, stress rupture, creep properties, impact ductility, strain response, stress relaxation behaviour, and so on are some of the most important physical and mechanical properties of Ni-superalloys. This article thoroughly reviews various studies on these properties, how and by what factors they are affected, and how they can be improved. Another important factor to consider when making Ni-superalloy castings is defect formation, which can affect the properties of the final product. Freckle defects, hot tears, porosities, and slivers are some of the major defects that occur in Ni-superalloys during the casting process. This article also reviews in detail about these defects, how they form, and how they affect the final product. These defects were found to have a significant influence on a variety of properties, such as creep, fatigue behaviour, and fracture mechanism. Topics and areas such as reinforcement of Ni-superalloys with the help of CNCs and 3D printing of Ni-superalloys that can provide scope for potential future research are highlighted based on the above-reviewed papers.