Mechanical, Metallurgical and Wear Behavior of Thermally-sprayed High Entropy Alloy Coating on Al7075 Substrate for Aerospace Applications

Aluminum alloys are widely used in various applications due to its favorable properties such as lightweight, high strength to weight ratio as well as corrosion resistance. Among its alloys, Al7075 is commonly used for its lightweight and high strength-to-weight ratio characteristics, making it ideal for aerospace components such as aircraft wings, landing gear, gearboxes, and structural support components. However, its lower hardness and limited wear resistance can restrict its use and life span. High entropy alloys (HEAs) are emerging as promising coating materials for improving performance, characterized by their composition of five or more principal elements. This study focuses on depositing HEA coatings, specifically AlFeCoCrMo, AlFeCoCrMoW, and AlFeCoCrMoV, onto Al7075 substrate to enhance its mechanical properties and wear resistance. The research involves a systematic investigation of these coatings, examining aspects such as porosity, microstructure, phase formation, microhardness, and wear resistance (ASTM G65). The goal is to understand how the addition of elements like W and V affect phase formation, hardness, and abrasion resistance of flame-sprayed AlFeCoCrMo HEA coatings. It is likely that thermally-sprayed HEA coatings will significantly improve the metallurgical, mechanical, and wear characteristics of Al7075 substrates. This advancement improves durability and wear resistance, extending Al7075’s lifespan in aerospace applications.