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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.

PurposeThis research work focuses on implementing this methodology in reducing the rejection rate of the turbocharger component problem that occurs during the manufacturing process. Using design, measure, analyze, improve and control (DMAIC) processes, it has been identified that clamping pressure on the component is one factor that affects quality. The impact of clamping pressure is studied to arrive at the ideal clamping pressure in which the rejection rate is the least.Design/methodology/approachQuality is the keyword in manufacturing where the production of a defect-free component is the most sought out objective. The definition of quality keeps getting refined throughout the years, from making products with no defects to minimizing rejection and scrap in the manufacturing process. Production facilities, to achieve this purpose, have adopted various methods and use of the DMAIC of Six Sigma methodology is one among them.FindingsThe study identified the fault causing the defect and suggested the methods to correct the fault. The suggestions would result in reducing the losses arising due to this and similar rejection causes.Originality/valueWith the adoption of DMAIC, it is found that misalignment of top and side clamp pressure is zero. When the side clamp pressure is at 75 PSI, and top clamp pressure is changed from 90 PSI to 95 PSI, the mean of responses is greater than the side clamp pressure of 80 PSI. Therefore, from the three-combination top clamp pressure of 100 PSI and the side clamp pressure of 75 PSI is the optimal condition.

Measurement of roundness and contour is the essential process taking place in many manufacturing industries. Parts and components having round edges are typically produced in many industries for various applications like automobile shafts, gears, bearings and exhaust pipes. Incorporation of six sigma process can improve the quality of the measuring processes. Six Sigma methodology deals with using a strategy that attempts to reduce variation and to improve the quality through Six Sigma. This can be carried out by employing two different Six Sigma procedures. This article points out methods to reduce the lead time of Coordinate Measuring Machine inspection by introducing various measurement techniques and programming and design of holding fixtures. The methodology of execution of the measuring methods is initiated with the identification of problems, followed by analysis, identification, implementation and improvement. It is concluded that after the incorporation of the inspection lead time, there was considerable improvement in time spent for the entire measurement process.

In natural / casual conversations, people tend to have their own unique style of speaking/ chatting; certain phrases only they use, style of typing, customized grammar, nicknames etc. These ‘imperfections’ make the dialogue more human; we are able to identify people from their unique style of chatting. Conversational chatbots trained on clean text won't be able to capture these nuances. We propose a method to capture these quirks in the form of a chatbot with a novel NLG (Natural Language Generation) architecture; In the form of a convolutional transformer. WhatsApp chats between two users were cleaned and exported for training the model. The dataset had Unicode characters for foreign lexicon, emojis, and personalised grammar / texting patterns. The model is able to capture these traits in conversation for short responses.

A new plating bath has been optimized based on nickel, trivalent chromium and cobalt to improve micro hardness and corrosion resistance of zinc pressure die cast parts. The coating of Ni-Cr-Co on Zinc PDC flash replaces hard molybdenum and copper and its alloys used in gear and wheels in automobiles. Salt spray tests were performed to study the corrosion resistance of developed coatings on Zinc pressure die cast parts in sea water medium. The results are presented and discussed.

Every industry has to ensure a quality check so as to ensure that the products manufactured by them are safe for the consumers. During this process, a lot of wastage occurs due to rejection. Because of this rejection a lot of time, money, resources and manpower are wasted. This research work focuses on minimising this rejection and also to ensure maximum recovery from the rejected material by Poka Yoke. Furthermore, the rejected products from a parent company are smuggled and sold in the market without the parent company's notice, thereby spoiling their reputation. To elude this situation, hallmarking by engraving technique is also suggested. This helps in maintaining accountability of the rejected goods and also in preventing them from reaching the black market.