Effect of surface treatment on the mechanical and interfacial properties of single carbon fibre

• Main Author: Ci, Ruixiang
• Other Authors: Chen Zhong
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/62368
• Institution: Nanyang Technological University

Carbon-fibre reinforced composite (CFRC) is widely used in industries nowadays due to its excellent mechanical properties. It is crucial to study the interface between the carbon fibre and the matrix as insufficient interfacial adhesion easily leads to failure of the composite. The interfacial adhesion between untreated carbon fibre and epoxy in a CFRC is poor, and surface treatment is thus required to enhance the interfacial adhesion. Acid treatment and coating are two important techniques for surface treatment, and it is important to understand the effect of different conditions for these two techniques on the mechanical and interfacial properties of carbon fibre. Single carbon fibre is investigated on the micro level, and many parameters can be used to characterize the mechanical and interfacial properties, including tensile strength, Young’s modulus, apparent interfacial shear stress (IFSS) and interfacial fracture toughness. These parameters are measured using microtensile test and microbond test, two convenient methods with simple operation and reasonable results. Various models have been developed to describe the interfacial fracture toughness, and the most popular model links it with the critical energy release rate of interfacial crack. Experimental results show that the optimum acid treatment time is 15 to 30 minutes, and the optimum coating material is NiCuP, based on the abovementioned methodologies.