Steel, also known as iron alloy, is found 35% of the whole mass of the Earth. It is found in many applications due to its unique properties. Alloying elements provide the backbone support for iron, improving its mechanical, physical, chemical, and structural properties. Failure of steel is due to chemical reaction i.e., corrosion, and it is unavoidable, but it can be prolonged. Applications such as marine have a salt corrosive environment. High-temperature applications such as power plants, gas turbines components, and combustion engine components accelerate air oxidization at higher temperatures. Protection coating alters the chemical composition of alloy surfaces by using techniques like conversion coating, mechanical alloying, ion beam implantation, laser cladding, and thermochemical treatments. Protection coatings adhere to the steel surface and prevent steel from direct contact with the environment, which is formed by chemical vapor deposition, physical vapor deposition, electroplating, chemical bath, sol-gel, thermal spraying, and hot-dip coating. These coatings are used to reduce the chemical reaction in accelerated corrosion environments so that the life span of the steel is further enhanced, thereby decreasing the replacement cost. These coating methods and coating materials play a vital role in corrosion and other corrosion-associated failure protection. The coating materials like chromium and cadmium produce carcinogenic gases. Coating methods such as thermal spraying, hot-dip coating, and thermochemical treatment produce by-products that affect the environment by releasing pollutants. It is essential to choose coating materials and methods that do not influence the environment and ecosystem. In this work, processing techniques available to prepare the protective coating for steel are discussed. The methods used to enhance the properties of steel and the various real-time characterizations are also discussed. In addition, challenges and opportunities in the proposed scope are also included.

The aerospace industries are focused on lightweighting with alloys having good tensile strength, fracture toughness, fatigue resistance, and corrosion resistance. The friction stir welding technology is one of the productive techniques in the aerospace industry to join such alloys with little ease. This paper deals with the composition of alloying elements that makes the structure lightweight and the impact of the precipitates evolved out of the selected alloying elements on the mechanical properties such as tensile strength and hardness of the joint in the aerospace alloys such as AA2xxx conventional aluminium alloys, AA2xxx lithium-based aluminium alloys, and AA7xxx aluminium alloys.

Finding a suitable biomass sample for the pyrolysis process with proper physicochemical properties is a challenging one as it has several criteria and attributes. Multicriteria decision-making (MCDM) represents a systematic approach for helping decision makers in diversified field. In this study, the application of the digraph and matrix approach is described for the selection of the most appropriate biomass material for yielding more liquid oil via thermochemical conversion. A biomass material selection index (BMSI) is proposed that evaluates and ranks the selected materials. The index is derived from a material selection attributes function and acquired from a material selection attributes digraph. The digraph is developed making an allowance for material selection attributes and its relative importance related to pyrolysis. A sequential procedure to assess the biomass material selection index is recommended in this study. Among the selected materials, this study demonstrated a sunflower shell with a higher index. At the end of the study, the prediction is also validated by conducting the experimental research.

Temperature-sensitive cure kinetics based on bisphenol A oligomeric diglycidyl ether and branching diphenylmethane di-isocyanate, polymer aliphatic or lower molecular weight aromatic amines, and polypropylene and epoxy composites were examined. Polypropylene networks are formed initially, followed by amine hardeners interfering with epoxy oxirane rings to frame linear oligomers. Finally, the system is formed by a reaction between amines obtained in the second phase and epoxy oxirane rings during the curing step. This three-stage treatment was illustrated. The activation energy was calculated using the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose isoconversational approaches to cure degree. The Ea-to- correlation was determined using these approaches, revealing that the research curing systems exhibited autocatalytic effects. Among the materials studied, compounds with low molecular weight aromatic amines had the strongest and longest-lasting tensile characteristics. There are numerous advantages to slow curing and discrete stages of composite creation, including better mechanical properties.

The prospect of solar distillation is growing due to the fact that it offers an ecologically sound as well as cost-effective method of supplying drinking water. Solar-powered stills have become the most widely used, needed, and practically feasible methods to harness the power of the sun, and they provide an abundance of potable and agriculturally useful clean water. The purpose of this review is to provide a comprehensive overview of the state of the art in solar still research by compiling investigations that use various methods of modifying the absorber plate of the solar stills to increase their performance. Specifically, a thorough examination of the effect of integrating various biomaterials, such as egg shells, carbonized balsa wood, peanut shells, conch shells, snail shells, and so on., over the absorbing surface of the solar still was carried out. This review article provides value because it gives a framework for systematically evaluating how the application of different biological waste materials over the absorber plate affects the daily production rate of a solar-powered still. The review revealed that there is still enough room to improve the performance of the stills through the modification of the absorber surface with bio-waste materials.