Fabrication of ternary composites with controlled surface microstructure using a cascaded suspension deposition method

Abstract Fabrication of multifunctional materials via incorporation of the third component into structural composite laminates is of great interest, especially for manipulating surface properties. However, achieving a uniform, well‐dispersed surface microstructure in ternary composites is quite challenging by using the traditional fabrication processes. In this article, a novel cascaded suspension deposition method is presented to introduce well‐dispersed short fibers into the molded laminates, allowing the control of the surface properties of the resulting ternary composite. Towards this goal, the micron‐sized, nickel‐coated carbon (NiC) fibers are uniformly deposited on a glass fabric surface by the proposed method. The deposited fabric is then used to fabricate NiC/glass/epoxy composite laminate by vacuum assisted resin transfer molding (VARTM). The deposition morphology on the glass fabrics and the fabricated laminates is investigated by assessing: (i) spatial uniformity of fiber volume fraction; (ii) degree of dispersion; and (iii) process‐induced orientation and degree of alignment. To demonstrate the flexibility of the proposed method, the effects of fiber concentration, fabric architecture, and resin flow are studied. The experimental results reveal that, in all fabrication cases, the cascaded suspension deposition technique is capable of depositing short fibers on the fabric surface with a uniform fiber volume fraction and excellent dispersion with random orientation. In addition, it is observed that the resin flow during VARTM does not considerably disturb the deposition‐induced microstructure of the NiC fibers, which allows the successful fabrication of ternary composites by VARTM.