Performance evaluation of thick carbon fiber‐reinforced laminates manufactured using six‐magnetron microwave system

Abstract Microwave curing is a fast, energy‐efficient, and a viable alternative to conventional thermal curing processes. It has been widely adopted for processing carbon fiber‐reinforced polymer composites because the high electrical conductivity of carbon fibers enables strong microwave coupling. In this study, IM7/Cycom 5320‐1 unidirectional prepreg has been used to fabricate 64‐layer laminated composites. Symmetric cross‐ply ([0°/90°] 16S ) and a quasi‐isotropic ([45°/90°/−45°/0°] 8S ) layup have been investigated. A custom‐built six‐magnetron microwave applicator and an autoclave were employed to manufacture the composite panels. Degree of cure of the manufactured laminates was evaluated via differential scanning calorimetry. Interfacial bonding and porosity of the microwave‐cured laminates were assessed and compared with autoclave‐cured specimens using optical microscopy and micro‐computed tomography. Mechanical performance of the microwave‐cured composites has been juxtaposed to autoclave‐cured composites in terms of the uniaxial tensile, three‐point flexural, and open‐hole tensile properties. Experimental results demonstrate that microwave‐cured laminates possess void content, degree of cure, and mechanical properties as good as those of laminates manufactured by autoclave. The microwave curing cycle reduced the overall processing time by 23.3%, exhibited up to 16.75% higher tensile strength, and 23.20% higher flexural modulus as compared to the autoclave‐cured laminates. Scanning electron microscopy has been used to investigate the surface topology of the manufactured specimens. Outcomes of this study highlight the potential of multi‐magnetron microwave curing as a viable, energy‐efficient alternative for fabricating high‐performance carbon fiber‐reinforced polymer composites. © 2026 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.