Magnet assisted composite manufacturing: A novel fabrication technique for high-quality composite laminates

Abstract

A novel fabrication method, Magnet Assisted Composite Manufacturing (MACM), is developed to produce high-quality composite laminates out of an autoclave. This technique involves the placement of high-temperature Neodymium permanent magnets on a vacuum bag to generate sufficiently high consolidation pressure during cure, thus eliminating the necessity of using an autoclave. The objective of this study is to demonstrate the ability of MACM to fabricate high-performance laminates, which have comparable mechanical properties, fiber volume fraction, and void content to those achieved by autoclave curing. Towards this goal, eight-ply, woven carbon/epoxy laminates were fabricated in an oven by MACM and in an autoclave using the same thermal cycle. The thickness of the laminates cured by MACM indicated that an effective consolidation pressure of 0.29 MPa (42 psi) can be generated by the magnets during cure at 177°C (350°F). The high flexural properties, high fiber volume fraction, and the low void content of the laminates fabricated by MACM validated the feasibility of this process as a lower-cost alternative to autoclave cure, without compromising the part quality. Considerable reduction of void content to under 1% was also achieved by applying magnets during cure when the resin viscosity was at a minimum. POLYM. COMPOS., 40:159–169, 2019. © 2017 Society of Plastics Engineers.