Self-healing Ceramic Matrix Composites: A Monograph

By DIMITRIOS E. ANASTASIOU

Ceramic matrix composites are very useful high-tech materials, but their brittle nature places limitations. These limitations can be overcome with modern self-healing techniques. This monograph contains specialized and up-to-date information, especially valuable for researchers and students in materials science, engineering and ceramic composites technology, and also for engineers and scientists in the aerospace, building and construction, energy, and similar technological areas.

• Language: English
• Publisher: ODE EDITIONS
• Release date: Dec 15, 2021
• ISBN: 9786188540521

Book preview

Dimitrios E. Anastasiou

Self-healing

Ceramic Matrix

Composites

A Monograph

ISBN: 978-618-85405-2-1

Copyright © 2021-22 by Dimitrios E. Anastasiou. All Rights Reserved.

No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other non-commercial uses permitted by copyright law. For permission requests, write to the publisher, addressed Attention: Permissions Coordinator, at the e-address: [e-mail]

Contents

Preface

Abstract

Introduction

Production Methods

The Powder Route

The Liquid Phase Route

Spark Plasma Sintering (SPS)

Hybrid Routes

3D-Printing (3DP) hybrid routes

Self-healing: The Natural Way

Self-healing in Polymer-Matrix Composites

Self-healing of damage in Ceramic Matrix Composites

Matrix and reinforcement

Self-healing Coatings

Carbon/Carbon composites: A challenging case

CMCs with SiC and Si3N4 Agents

The Role of the Interphase

Working at the Nano-scale

State of the Art Nano-CMCs

Carbon Nanotubes CMCs

BN Nanotubes CMCs

Graphene nanoplatelets CMCs

Bio- CMCs

Chemistry-related Issues

Recent Advances

A gap in current research

Conclusion

Curriculum Vitae

Preface

Self-healing Ceramic Matrix Composites offer an innovative approach to composite ceramic matrices enabling them to heal under certain conditions, focusing on the latest advances and the development of new materials. 

The specialized information contained in this monograph were written with the hope to be highly valuable to researchers and graduate students in materials science, engineering and ceramic composites technology, and engineers or scientists, in the aerospace, building and construction, energy, and other sectors. It is also intended to be a guide for teaching related subjects to college students.

The choice of the references was made with the intention of being the most relevant to the subject, according to the author's opinion, and does not mean that the publications that were excluded from this work, are- in any way- of lower significance.

This monograph consists of seven main chapters. The first is a detailed introduction in self-healing ceramic matrix composites. The second deals with production methods and the third with general considerations. Chapter 4 is about the special case of Self-healing Carbon/Carbon composites and Chapter 5 is looking into nano-scale self-healing CMCs. Chapter 6 presents some chemistry issues and Chapter 7 looks into the latest advances in the field.

Self-healing Ceramic Matrix Composites

A Monograph

Dimitrios E. Anastasiou

Abstract

Ceramic Matrix Composites appeared recently as the new trend for high-tech substitutes to alloys in high temperature operational environments. Cracks are made during the fabrication stage or can be made during the working self-life of CMCs under adverse environmental conditions. Cracks have to be repaired as soon as possible to prevent failure or even total collapse of the material. Oxygen diffusion into the composite, at high temperatures, is usually the main attack factor. The best solution to protect these materials seems to be the- biologically inspired- self healing mechanisms, promising to provide the most accurate, fast and cheap therapy, if designed properly. Self-healing can work on matrix or interphase, via embedded substances or via coatings, in micro- or nano- level, protecting the composite from oxidation and spallation. In most cases it is based on the formation of a viscous liquid oxide, which flows and fills the gaps, preventing further oxygen penetration. Temperature range is crucial for the oxide stability in the liquid phase. With novel materials in mind, such as Carbon Nanotubes and Graphene, modern scientific research is looking forward to developing new amazing applications.

Keywords:

self-healing, ceramic matrix composites, carbon/carbon composites, oxidation, protection, crack-healing, coatings, carbon nanotubes, graphene, boron nitride nanotubes, bio-composites.

Acknowledgments:

Special thanks to Professor Vassilis Kostopoulos (University of Patras, Department of Mechanical and Aeronautical Engineering) for giving me the idea to carry out this work.

Introduction

Composite materials are materials made from two or more constituents, having different physical or chemical properties, combined to a new material with significantly different properties than the individual components, which however remain separate and distinct within the finished product (2-phase system). Currently, organic composites- thermoset or thermoplastic- dominate this advanced materials area but their use is limited to low temperature applications (<300oC). Carbon Fiber Reinforced Polymers (CFRP) is a wide category of easy to process organic composites with well-known techniques and a large applications field. At higher temperatures Ceramic Matrix Materials are employed and found to have outstanding performance in temperatures above 1000oC. A Ceramic is an inorganic non-metallic solid made up of either metal or non-metal compounds that have been shaped and then hardened by heating to high temperatures. In general, they are hard, corrosion-resistant and brittle. Advanced ceramics are substances based on metal oxides like alumina (Al2O3), inorganic non-metal oxides like silica (SiO2) and non-oxides like silicon carbide (SiC) or silicon nitride (Si3N4). Unlike traditional clay-based ceramics, advanced ceramics do not necessarily need to be directly earth-derived. The main disadvantage of monolithic ceramics is their low fracture toughness, which leads to brittle fracture and detrimental thermal shock resistance. Ceramic Matrix Composites (CMCs) [1-4] consist of reinforcing phases (particles, whiskers, short fibers, nano-reinforcements, continuous fibers, ...) mainly fibers and a ceramic matrix (oxide, carbon, Silicon Carbide, ...) to create composite materials with new and enhanced