Chapter 1 BMS - Introduction to Materials OCT 2024 PDF

BASIC MATERIALS SCIENCE OCTOBER SEMESTER 2024 CHAPTER 1 : INTRODUCTION TO MATERIALS SCIENCE AND ENGINEERING 1. 1 INTRODUCTION 1.2 CLASSIFICATION OF MATERIALS 1.3 MATERIALS SELECTION 1.4 MATERIALS SAFETY DATA SHEET (MSDS)  1.1 INTRODUCTION Materials - defined as a substanc...

BASIC MATERIALS SCIENCE OCTOBER SEMESTER 2024 CHAPTER 1 : INTRODUCTION TO MATERIALS SCIENCE AND ENGINEERING 1. 1 INTRODUCTION 1.2 CLASSIFICATION OF MATERIALS 1.3 MATERIALS SELECTION 1.4 MATERIALS SAFETY DATA SHEET (MSDS)  1.1 INTRODUCTION Materials - defined as a substance that is intended to be used for certain applications. Materials Science – involves investigating the relationships that exist between the structures and properties of materials. Materials Engineering – correlation of structure-properties of materials to produce a predetermined set of properties for the engineering applications.  1.1 INTRODUCTION What is material science? Definition 1: A branch of science that focuses on materials; interdisciplinary field composed of physics and chemistry. Definition 2: Relationship of material properties to its composition and structure. What is a material scientist? A person who uses his/her combined knowledge of physics, chemistry and metallurgy to exploit property-structure combinations for practical use. DISCUSSION  Material Science is the investigation of relationship among : Structure: At the atomic level: arrangement of atoms in different ways. (Gives different properties for graphite than diamond both forms of carbon.) At the microscopic level: arrangement of small grains of material that can be identified by microscopy. (Gives different optical properties to transparent vs. frosted glass.) Properties are the way of material responds to the environment. For instance, the properties are the responses to mechanical, electrical and magnetic forces, respectively. Other important properties are (transmission of heat, heat capacity), (absorption, transmission and scattering of light), and the in contact with the environment (like corrosion resistance). Processing of materials is the application of heat (heat treatment), mechanical forces, etc. to affect their microstructure and, therefore, their properties Performance - behavior in a particular application, eg : corrosion, oxidation behavior  Relationship among the components Arrangement of internal components Microsopic & Macroscopic (bulk) Response to external stimulus Mechanical, electrical, thermal, magnetic, Method of preparing optical material Behavior in a particular application  Steel Production Chocolate Production CHOCOLATE ALSO A PART OF MATERIALS SCIENCE ! SIMPLE TO COMPLEX  Materials development Construction of Eiffel tower. During steam engine era In Scotland WATCH :  1.2 CLASSIFICATION OF MATERIALS Metals Cermets MCM Ceramics CCM Glass-ceramics Composite GCCM PCM s FRG Polymers Glass MCM Metal composite materials CCM Ceramic composite material PCM Polymeric composite material GCCM Glass-ceramic composite material FRG Fiber-reinforced glass  CLASSIFICATION OF MATERIALS Metals Non localized electron Ceramics & Glasses Polymers good conductors of thermally and very large molecules electricity and heat electrically insulating low density, low weight lustrous appearance resistant to high maybe extremely susceptible to temperatures and flexible corrosion harsh environments strong, but deformable hard, but brittle Ductile  PROPERTIES OF METALS -High toughness -High melting point -good conducter of -Ductile heat -easy to oxidise -high tensile strength -luster -Strong van der waals -Heavy in weight force -Strong attraction High conductor force electric -malleable -solid at room temp -Shiny material -High density -High heat specific -High reactivity  ADVANCED MATERIALS BIOMATERIALS SEMICONDUCTORS COMPOSITES Implanted in human Electrical properties Consist of more than on body between conductors and type of materials Biocompatible to body insulators tissues  generally are poor electrical and many are relatively strong thermal conductors. and ductile at room most have low to medium strengths. temperature. most have low densities. some have good strength at most are relatively easy to process high temperature. into final shape some are transparent. most have relatively high Ductile / soft electrical and thermal Low thermal stability conductivities. METALLIC POLYMERIC MATERIALS MATERIALS have a wide range of strength from low to very high; generally have high - some have very high hardness and are CERAMIC COMPOSITE strength-to-weight ratios mechanically brittle. MATERIALS MATERIALS (e.g. carbon-fiber epoxy High thermal and materials). electrical resistance - some have medium High resistance to strength and are able to corrosion NATURAL be cast or formed into a High temperature MATERIALS variety of shapes (e.g. stability fiberglass-polyester materials). - some have useable strengths at very low cost. Figure 1 Main classes of engineering materials  HOW DO WE TEST MATERIALS MECHANICAL TEST - strength, ductility, toughness, hardness of materials Tensile tests Bend tests Compressive tests Fracture test Hardness test  ELECTRICAL TEST Earth Continuity Test Insulation Resistance Test · Leakage Test Voltage Test  CHEMICAL TEST Elemental Analysis Chemical Exposure Trace Contamination Detection  1.3 MATERIALS SELECTION Different factors to be considered during the selection of materials. Material properties Nature of property Requirement Mechanical Properties Tensile strength Hardness Ductility Impact strength Wear resistance Corrosion resistance density Thermal Properties Specific heat / heat capacity Thermal conductivity Thermal expansion Thermal resistance Shock resistance Thermal fatigue Material structure Atomic arrangement Bonding nature Optical properties Refractive index Boeing 757-200  Discussion No. 1 (a) Name the important criteria for selecting materials to use in a protective sport helmet. (b) identify materials that would satisfy these criteria. (c) why would a solid metal helmet not be a good choice?  1.4 MSDS What do MSDSs contain? Identification of the product Composition/ information on ingredients. (Exact formulations & details of non-hazardous components not required – protects from rival manufacturers) Alcohol Ethoxylate