Processing of Polymer Matrix Composites

Processing and Applications

P.K. Mallick

• Publisher: CRC Press
• Year: 2017
• ISBN:
  9781351643993
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Polymer matrix composites are finding increasing number of applications due to their high weight-saving potential as well as unique characteristics, such as high strength-to-density ratio, fatigue resistance, high damping factor, and freedom from corrosion. While many textbooks are available on the mechanics of polymer matrix composites, few cover their processing. Processing of Polymer Matrix Composites fills this gap. The book focuses on the major manufacturing processes used for polymer matrix composites and describes process details, process parameters and their effects on properties and process-induced defects, and analytical and experimental methods used for understanding process conditions. The book describes fibers, thermosetting and thermoplastic polymers, and interface characteristics that are important from the standpoint of both design and processing. It also emphasizes the applications of process fundamentals for both continuous fiber and short fiber polymer matrix composites. In addition the book considers quality inspection methods, tooling, and manufacturing costs and environmental and safety issues.

1Introduction

P. K. Mallick

In the last few decades, polymer matrix composites (PMCs) have become an important and useful class of structural materials. They are used in many aerospace, automotive, industrial and consumer applications, often competing with other structural materials, such as steels, aluminum alloys, and titanium alloys. In a PMC, high-strength and high-modulus fibers are used as reinforcement, and a polymer serves as the matrix material. The combined material has a much higher modulus and strength than the polymer matrix itself, and hence, it is often called a fiber-reinforced polymer (FRP).

PMCs have found much greater use than either metal matrix composites or ceramic matrix composites in aerospace, automotive, and other industries, primarily because of their lower density, high strength-to-density ratio, high modulus-to-density ratio, and relative ease of processing. The lower density of PMCs compared to metal matrix composites and ceramic matrix composites is due to the lower density of polymers compared to metals and ceramics. The density of polymers commonly used for PMCs is in the range of 0.9–1.4 g/cm3. The density of reinforcing fibers is also very low, typically between 1.4 and 2.6 g/cm3. Depending on the fiber type and fiber volume fraction, the density of PMCs is between 1.2 and 2 g/cm3. Because of such a low density, the strength-to-density ratios and, in many cases, modulus-to-density ratios of PMCs are comparatively higher than those of metals (Table 1.1). This gives a great weight saving opportunity in many applications if a PMC is selected instead of metals.

Table 1.1Comparison of Properties of a Few Selected Metals and Composites

Material	Density (g/cm3)	Tensile Modulus (GPa)	Tensile Strength (MPa)	Tensile Modulus-to-Weight Ratio (106 m)	Tensile Strength-to-Weight Ratio (103 m)
SAE 1010 steel (cold worked)	7.87	207	365	2.68	4.72
AISI 4340 steel (quenched and tempered)	7.87	207	1722	2.68	22.3
6061-T6 aluminum alloy	2.70	69	310	2.60	11.7
7178-T6 aluminum alloy	2.70	69	606	2.60	22.9
Ti-6Al-4V titanium alloy	4.43	110	1171	2.53	26.9
High-strength carbon fiber–epoxy composite (unidirectional)	1.55	137.8	1550	9.06	101.9
High-modulus carbon fiber–epoxy composite (unidirectional)	1.63	215	1240	13.44	77.5
E-glass fiber–epoxy composite (unidirectional)	1.85	39.3	965	2.16	53.2
Kevlar 49 fiber–epoxy composite (unidirectional)	1.38	75.8	1378	5.60	101.8
Carbon fiber–epoxy composite (quasi-isotropic)	1.55	45.5	579	2.99	38
SMC composite (isotropic)	1.87	15.8	164	0.86	8.9

Notes: (1) For unidirectional composites, the fibers are unidirectional, and the reported tensile properties are in the direction of fibers. Properties in the direction normal to the fibers are much lower. (2) Tensile modulus-to-weight ratio is calculated by dividing the tensile modulus with specific weight, which is defined as the weight per unit volume and is obtained by multiplying density with the acceleration due to gravity (9.81 m/s2). Tensile strength-to-weight ratio is calculated in a similar way.

In a PMC, the matrix can be either a thermoplastic polymer, such as polyether ether ketone (PEEK) and polypropylene (PP) or a thermosetting polymer, such as an epoxy and a polyester. Fibers commonly used as reinforcement are ...

Table of contents

• Cover
• Half Title Page
• Title Page
• Copyright Page
• Dedication
• Contents
• Preface
• Chapter 1 Introduction
• Chapter 2 Fiber Architecture
• Chapter 3 Matrix Materials
• Chapter 4 Processing Fundamentals
• Chapter 5 Bag Molding Process
• Chapter 6 Compression Molding
• Chapter 7 Liquid Composite Molding
• Chapter 8 Filament Winding
• Chapter 9 Pultrusion
• Chapter 10 Forming of Thermoplastic Matrix Composites
• Chapter 11 Joining and Repair
• AppendixHealth and Safety Issues
• Index