Chapter 1. Introduction

Chapter 1. Introduction <Objectives> 1. List 6 property classifications of materials. 2. Cite the four components of the discipline of materials science and engineering, and briefly describe the interrelationships between these components. 3. Cite three criteria that are important in the materials selection process. 4. List three primary classification and the other three types of materials.

1.1 HISTORICAL PERSPECTIVE • Materials are deep-seated in our culture : transportation, housing, clothing, communication, recreation, Food production … • The earliest humans had access to very limited number of materials : stone, wood, clay … • They discovered techniques for producing materials. • It was discovered that the properties of a material could altered by heat treatments or the addition of other substances. • Came to understand the relationships between the structural elements of materials and their properties.

1.2 MATERIALS SCIENCE & ENGINEERING • Structure : the arrangement of its internal components - subatomic, atomic, microscopic, macroscopic • property : to evoke some type of response about external stimuli - mechanical, electrical, thermal, magnetic, optical, deteriorative • Processing : to control the structure of materials • Performance : a function of its properties Basic science & Understanding Social needs & experience

1.3 WHY STUDY M.S.&E.? ☞ to select the right material • The in-service conditions must be characterized. • Any deterioration of material properties that may occur during service operation. • Economics : What will the finished product cost?

1.4 CLASSIFICATION OF MATERIALS • Metals - combinations of metallic elements - good conductors of electricity and heat - not transparent - lustrous (polished metal surface) - strong - deformable • Ceramics - compounds between metallic and nonmetallic elements - insulative to passage of electricity and heat - more resistant - hard, but brittle • Polymers - organic compounds that are chemically based on carbon, hydrogen, and other non-metallic elements - have very large molecular structures - low densities - flexible

1.4 CLASSIFICATION OF MATERIALS • Composites - consist of more than one material types • Semiconductors - have electrical properties that are intermediate between the electrical conductors and insulators - are extremely sensitive to the presence of minute concentrations of impurity atoms • Biomaterials

1.5 ADVANCED MATERIAL • By high technology, we mean a device or product that operates of functions using relativelyintricate and sophisticated principle. : VCRs, CD players, computers, spacecraft … • Have been enhanced or newly developed, high performance materials • Expensive 1.6 MATERIALS OF THE FUTURE • Smart Materials • : ①shape memory alloys ②piezoelectric ceramics ③magnitostrictive materials ④electrorheologicals/magnetorheological fluids • Nanotechnology 1.7 MODERN MATERIALS NEEDS

Chapter 1. Introduction

Chapter 1. Introduction

Presentation Transcript

Chapter 1 Introduction

Chapter 1: Introduction

Chapter 1: Introduction

Chapter 1: Introduction

Chapter 1 Introduction

Chapter 1 Introduction

Chapter 1: Introduction

Chapter 1: Introduction

Chapter 1: Introduction

Chapter 1 Introduction

Chapter 1: Introduction

Chapter 1 INTRODUCTION

Chapter 1: Introduction

Chapter 1: Introduction

Chapter 1: Introduction

Introduction: Chapter 1

Chapter 1. Introduction

Chapter 1 Introduction

Chapter 1: Introduction

Chapter 1: Introduction

Chapter 1: Introduction

Chapter 1: Introduction