Adhesive strength between TiNi fibers embedded in CFRP composites

The effect of treating the surface of TiNi fiber by acid etching on the interfacial adhesive strength between the TiNi fiber and the CFRP matrix is investigated. For acid etching of the TiNi fiber, acid solutions of 36% HCl, 15% HNO3, 97% H2SO4, and 3% HF+15% HNO3 were used. The composites were fabricated by curing at 180 °C for 2 h using hot-pressing. The interfacial adhesive strength between the embedded TiNi fiber and the CFRP matrix was evaluated by a pullout test. It was found that surface treatment of the TiNi fiber by acid etching improved interfacial adhesive strength.