Adhesion and Bonding in Composites

Ryutoku Yosomiya

• Publisher: CRC Press
• Year: 2020
• eBook ISBN: 9781000148831
• Topic: Physical Sciences
• Subtopic: Chemistry
• Index: Chemistry

This book deals with the roles played by the component material interface in composites, with special emphasis on methods used to improve the adhesion and bonding between them. It is helpful for scientists and engineers in the materials field and to engineers working with adhesives or composites.

1

Interfacial Characteristics of Composite Materials

1.1 Introduction

Composite materials are materials of composite structure comprising two or more components that differ in physical and chemical properties which have been combined to provide specific characteristics for particular uses. The boundaries between components are referred to as solid interfaces.

Recently, it has become popular to consider the boundary not as a contact interface without thickness but as an interphase with thicknesses on both components. That is, the concept involves the existence of a chemical and physical transient region or gradient in the boundary. For example, a fiber-reinforced composite material includes three phases: the surface of the fiber side, the interface between the fiber and the matrix, and the interphase. These phases are referred to collectively as the interface.

The characteristics of the interface are dependent on the bonding at the interface, the configuration, the structure around the interface, and the physical and chemical properties of the constituents. As a result the interface has a strong influence on the property of the composite material. In this chapter we describe interaction of the interface and structural change in the interface.

1.2 Composite Effect and Interfaces

A method for the estimation of composite material performance from the characteristics of fillers (reinforcing material: fiber, powder) and matrices (polymer, metal, ceramics) and from the configuration of the filler is generally called a law of mixture. In the most basic form of a law of mixture, some characteristics of a composite material are represented as a function of characteristics of constituent components and their volume fractions, as shown in Figure 1.1 [1].
For a composite material (characteristics: χ_c) that consists of component A (characteristics: χ_A, volume fraction: ϕ_A) and component B (characteristics: χ_B, volume fraction: ϕ_B), the basic formulas of a law of mixture are as follows:

Figure 1.1 Relation between the properties of composites and various laws of mixture. (Ref. 1)

$${\mathrm{\chi }}_{\text{c}}={\mathrm{\varphi }}_{\text{A}}{\mathrm{\chi }}_{\text{A}}+{\mathrm{\varphi }}_{\text{B}}{\mathrm{\varphi }}_{\text{B}}(1)$$

(parallel model, linear law of mixture, curve 1 in the figure) and

$$\frac{{\displaystyle 1}}{{\displaystyle {\mathrm{\chi }}_{\text{c}}}}=\frac{{\displaystyle {\mathrm{\varphi }}_{\text{A}}}}{{\displaystyle {\mathrm{\chi }}_{\text{A}}}}+\frac{{\displaystyle {\mathrm{\varphi }}_{\text{B}}}}{{\displaystyle {\mathrm{\chi }}_{\text{B}}}}(2)$$

(series model, curve 2 in the figure). The two curves exhibit theoretical upper and lower limits, respectively, based on a simple composite effect in general. A basic formula that generalizes (1) and (2) is

$${\mathrm{\chi }}_{\text{c}}^{\text{n}}={\mathrm{\varphi }}_{\text{A}}{\mathrm{\chi }}_{\text{A}}^{\text{n}}+{\mathrm{\varphi }}_{\text{B}}{\mathrm{\chi }}_{\text{B}}^{\text{n}}(3)$$

wherein n(–1 ≤ n ≤ 1) represents a structural parameter which indicates the proportion of the combination mode; that is, the parallel mode is predominant when n is close to 1 and the series mode is predominant when n is close to −1. In equation (3), when n has a small absolute value,

$$\text{log}{\mathrm{\chi }}_{\text{c}}={\mathrm{\varphi }}_{\text{A}}\text{log}{\mathrm{\chi }}_{\text{A}}+{\mathrm{\varphi }}_{\text{B}}\text{log}{\mathrm{\chi }}_{\text{B}}(4)$$

This function is intermediate in behavior between the parallel model and the series model (curve 3 in the figure, referred to as a logarithmic law of mixture).

The law of mixture described above is valid for a simple composite system with well-known structure in which the rule of additivity holds (no interaction in the ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Preface
• Table of Contents
• Contributors
• 1. Interfacial Characteristics of Composite Materials
• 2. Wettability and Adhesion
• 3. Surface Modification of Matrix Polymer for Adhesion
• 4. Surface Modification of Matrix Polymer by Craft Polymerization and Its Effect on Adhesion
• 5. Modification of Inorganic Fillers for Composite Materials
• 6. Surface Modification and Adhesion Improvement by the Blend Method
• 7. Adhesion of Resin to Metal
• 8. Bonding of Ceramic to Metal
• 9. Interfacial Modifications and Bonding of Fiber-Reinforced Metal Composite Material
• 10. Interfacial Effect of Carbon-Fiber-Reinforced Composite Material
• 11. Interface Analyses of Composite Materials
• 12. Interfacial Strength of Composite Materials
• Index