A review of heating mechanisms, process parameters, and defect-minimized densification applications of microwave sintering in metals

Abstract

Microwave sintering, an advanced materials processing technique, has garnered substantial attention due to its distinctive heating mechanism, which facilitates more uniform and efficient heating of materials, such as metal powders. This study constructs a comprehensive analytical framework for metallic microwave sintering across diverse material systems, covering the trajectory from initial physical response to final microstructural evolution. By integrating fundamental electromagnetic loss mechanisms with multivariable coupled control logic, it offers essential theoretical support for the advancement of microwave metal processing. This paper emphasizes the fundamental principles of microwave-material interaction, incorporating key parameters like penetration depth and absorbed power. Furthermore, the impact of various factors on the sintering process, including metal powder particle size, sintering power, heating rates, sintering temperature, and sintering time was explored. The applications of microwave sintering across a range of materials in detail, such as ferroalloys, copper alloys, titanium alloys, tungsten alloys, silver, aluminum alloys, magnesium alloys, and high-entropy alloys (HEAs) were also presented. Microwave sintering imparts higher density and improved uniformity, thereby enhancing properties such as hardness, strength, and corrosion resistance. Lastly, this paper also addresses the challenges linked with the microwave sintering of metals and offers a comprehensive outlook. This research aims to provide valuable guidance and aid to scholars in this domain by delivering a detailed overview of the current state of microwave metal sintering.