Advanced High-Temperature Structural Materials in Petrochemical, Metallurgical, Power, and Aerospace Sectors—An Overview

Metallic materials for structural applications are designed to withstand mechanical forces of high and varying amplitude in static or dynamic loading conditions, prevent undue deformation or premature failure, and ensure projected life and reliability of a component even in extreme and unanticipated conditions. Amplitude, magnitude, direction, duration, rate, and type of load determine the complexity and extent of the damage. The challenge is even higher if the component is exposed to temperatures above the equi-cohesive limit where the structural component is likely to undergo accelerated damages due to creep, oxidation, and allied degradation owing to the combined effect of mechanical stress and high temperature. Besides usual strategies of strengthening by precipitation, dispersion, alloying or solid solution, grain boundary, texturing, or phase transformation, mostly designed to arrest dislocation-mediated deformation assuming grain or phase boundaries, are stronger than the crystallite interior, a different strengthening approach based on non-metallic insoluble dispersoids, intermetallic phases or compound, and ceramic phases either as the matrix or reinforcement in a composite or even, hybrid materials is often considered prudent at elevated and/or dynamic loading conditions. Both intermetallic and ceramic phases as a monolith or dispersion are attractive due to their higher melting point, high specific strength, absence of or limited threats from creep, and/or fatigue-related damages at elevated temperatures. However, a universal strategy to develop materials for high-temperature structural applications is yet to emerge as service conditions and related threats vary from one application domain to another with varying degrees of challenges from load, oxidation, corrosion, erosion, creep, thermal fatigue, and shock, all at elevated temperature. In this contribution, we propose to present a critical review of characteristics of materials in terms of composition, microstructure, properties, and perceived working conditions for structural applications used in five specific sectors, namely petrochemical, metallurgical, power generation, aviation, and space. The limitations of currently used structural materials and alternatives available or explored are discussed in a comprehensive manner. The recent progress in developing different structural materials for high-temperature applications is briefly presented. The scope of future development in these sectors is highlighted with a critical assessment. For the successful development of newer materials, a concerted effort encompassing all major engineering aspects and an integrated system engineering approach is solicited.