The present review work elaborates the behaviour of aluminium matrix composites (AMCs) under various kinds of thermal stresses. AMCs find a number of applications such as automobile brake systems, cryostats, microprocessor lids, space structures, rocket turbine housing, and fan exit guide vanes in gas turbine engines. These applications require operation at varying temperature conditions ranging from high to cryogenic temperatures. The main objective of this paper was to understand the behaviour of AMCs during thermal cycling, under induced thermal stresses and thermal fatigue. It also focuses on the various thermal properties of AMCs such as thermal conductivity and coefficient of thermal expansion (CTE). CTE mismatch between the reinforcement phase and the aluminium matrix results in the generation of residual thermal stress by virtue of fabrication. These thermal stresses increase with increasing volume fraction of the reinforcement and decrease with increasing interparticle spacing. Thermal cycling enhances plasticity at the interface, resulting in deformation at stresses much lower than their yield stress. Low and stable CTE can be achieved by increasing the volume fraction of the reinforcement. The thermal fatigue resistance of AMC can be increased by increasing the reinforcement volume fraction and decreasing the particle size. The thermal conductivity of AMCs decreases with increase in reinforcement volume fraction and porosity.

High-Entropy Alloys (HEAs) have emerged as a novel class of materials exhibiting excellent mechanical, thermal, and corrosion-resistant properties. This paper discusses the application of HEAs in high-temperature steam environments, focusing on their potential as advanced materials for components in geothermal systems, nuclear power plants, and hydrogen fuel cells. These applications demand materials that can withstand harsh conditions, including elevated temperatures, aggressive fluids, and corrosive environments. With their unique composition of multiple elements in equimolar or near-equimolar ratios, HEAs present an intriguing prospect for addressing these challenges. The review summarizes recent research findings on the performance of HEAs in harsh conditions, highlighting their corrosion resistance. The versatility of HEAs, coupled with ongoing advancements in alloy design and processing techniques, opens new avenues for optimizing these alloys for enhanced durability and efficiency. A perspective on the current state of research and future prospects on the above has been discussed here. It sets the stage for further exploration of HEAs as promising candidates for sustainable and resistant materials in aggressive environment applications.

The global acceptance of additive manufacturing has evolved with time and has proven to provide promising solutions to varied critical requirements of the nuclear industry. The components of a nuclear reactor, when built using additive manufacturing techniques, offer high microstructural control, making them versatile for a range of properties. These properties can be made easily achievable and tailorable by using functionally graded materials. The nuclear components with a wide range of properties are essential, as the environment inside and outside the reactor varies drastically. This study reviews the current progress in additive manufacturing techniques used for manufacturing functionally graded materials for nuclear applications, highlighting the gradient design methodologies and processing techniques. Additive Manufacturing techniques such as selective laser melting uses multiple powder feeders, and mechanical pre-mixing of powders along with controlled process parameters for effectively fabricating functionally graded materials. These materials possess superior mechanical properties (such as microhardness ranging up to 890 H0_0.5 and compressive strength up to 2040 MPa for FeCrCoNiMo_0.5W_0.75), thermal conductivity and thermal properties compared to monolithic counterparts. A comparative analysis of the manufacturing capabilities of the additive manufacturing techniques, along with the usage of advanced computational techniques such as AI in optimising process parameters for desirable strength and low defect generation, is also presented. The study emphasises on the need for strategies such as process parameters optimisation and data-driven design to fully utilise the potential of additively manufactured functionally graded materials in the nuclear sector.