Material Science and Engineering Principles

• This chapter examines the relationships between material structures and properties.
• It covers the material selection process, engineering material types, and chemical bond nature.
• It provides insights into how material structure and processing influence properties.

Intended Learning Outcomes

• Comprehend the core principles of Materials Science and Engineering.
• Identify material selection criteria for specific applications.
• Recognize essential components in design, production, and utilization.
• Understand interrelationships between design, production and utilization of materials.
• Distinguish between material classifications and their characteristics

Fundamental Concepts

• Materials science investigates the relationships between material structures and properties.
• Materials engineering designs material structures to achieve desired properties based on structure-property correlations.

Materials Development Timeline

• Stone Age: Naturally occurring materials were used with minimal shape modifications.
• Bronze Age: Materials were refined using heat, chemical modifications (alloying), and mechanical deformation (cold working).
• Iron Age: Casting and alloying techniques were mastered, leading to steel development and the Industrial Revolution.
• Plastic Age: included the discovery and advancement of polymers, enabling plastics creation.
• Silicon Age: Silicon technology commercialization led to the information age and increased productivity.
• Future: Explores nanotechnology, biotechnology, energy/environmental advancements, and materials informatics.

Historical Eras of Material Development

• Stone Age (Beginning - 3000 BC): Involved using naturally occurring materials with shape changes.
• Bronze Age (3000 BC - 1200 BC): Included refining materials through heating, chemical modification (alloying), and mechanical deformation.
• Iron Age (1200 BC - Present): Characterized by the ability to design specific microstructures through heating and microstructure control.
• Plastic Age (1940 - Present): Marked the discovery of polymers and the ability to synthesize polymers.
• Silicon Age (1950 - Present): Featured commercialization of silicon technology and control of alloying accurately.
• Future: Focuses on nanotechnology, biotechnology, energy, environmental and information technology

Stone Age

• The Stone Age spanned from the start of human life to about 3000 BC.
• Naturally occurring materials were utilized with minimal modification.
• Tools and weapons were made by humans, using stones, wood, and animal bones.
• Simple techniques like chipping and grinding were used to make tools and weapons.

Bronze Age

• The Bronze Age lasted from 3000 BC to 1200 BC.
• Material manipulation saw significant advancements.
• Humans refined materials using heat to create bronze, an alloy of copper and tin.
• Stronger tools and weapons were enabled contributing to more complex societies and civilizations.

Iron Age

• The Iron Age spanned from 1200 BC to the present.
• Iron and steel mastery, by casting and alloying, revolutionized toolmaking and warfare.
• Powerful empires and advanced technologies rose forming the Industrial Revolution's foundation.

Plastic Age

• The Plastic Age began in the 1940s.
• Material innovation saw a new era with polymer discovery and commercialization.
• Industries were revolutionized by these synthetic materials via their versatility, durability, and affordability.
• Plastic revolutionized packaging, construction, electronics, and healthcare.

Silicon Age

• The Silicon Age started in the 1950s.
• Silicon technology saw commercialization, leading to integrated circuits, electronic devices, and the information age.
• Human productivity and connectivity saw a significant leap.
• Communication, entertainment, and countless other life aspects were transformed.

Future of Materials Science

• Nanotechnology, biotechnology, energy/environmental advancements, and materials informatics promise revolutionizing industries while solving global issues and promoting sustainability.

Four Components of Material Science

• Material structure, processing, properties, and performance are all interrelated.
• Structure, processing, properties and performance must be understood.
• Degrees of impact may vary on the three factors when adjusting one factor.

Engineering Materials

• Engineering materials are used in man-made structures and components.
• These materials can withstand applied loading without breaking or excessive deflection.

Classifications of Engineering Materials

• The major classifications are metals, polymers, ceramics, and composites.
• Each material can be classified according to properties.

Metals

• Have electrical and thermal conductivity.
• Metals are strong yet deformable and are used in structural applications.
• They form cation and ionic bonds with non-metals.
• Atoms arranged in an orderly (crystalline) manner.
• Metals are relatively strong and ductile at room temperature.
• Ferrous metals include steel, cast-iron, wrought iron, and malleable cast iron.
• Non-ferrous metals are all metals and their combinations, like Co, Sn, Al, Mg, and Ti.

Ceramics

• These are compounds of metallic and non-metallic elements bonded.
• "Keramikos" (Greek) is for pottery.
• “Keramos" is potter's clay, tile pottery.
• Composed of clay, minerals, cement and glass
• Most frequently composed of oxides, carbides, and nitrides.
• May be crystalline, non-crystalline, or a mixture.
• Lightweight with high strength, hardness, good heat, and wear resistance.
• Insulative and resistant to high temperatures compared to metals and polymers.
• Hard, but not brittle.

Polymers

• These are familiar plastic and rubber materials.
• Have a low density and are extremely flexible.
• Chemically based on C and H, and other non-metallic elements.
• Some are good insulators for electrical insulation applications.
• Natural types are cellulose, silk, wool, proteins, and nucleic acids.
• Synthetic types are nylon, polyethylene, Teflon, PVC, and polystyrene.
• The strength and ductility may vary.

Composites

• Composites are a two or more material mixture.
• Consist of selective filler (reinforcing material) and compatible resin (binder).
• An example is fiberglass (fiber-reinforced polymer).
• Exhibit strength of glass and flexibility of polymer.
• These display a combination of each component's best characteristics.
• Common examples are plywood, concrete, and cement.

Semiconductors

• Can conduct electricity at room temperature better than an insulator but less easily than a metal in solid or liquid form.
• Act as insulators at low temperatures.
• Possess electrical properties are intermediate between conductors and insulators.
• Semiconductor conductivity ranges from 10^3 to 10^-8 siemens per cm.
• Semiconductor elements include Silicon (Si), Germanium (Ge), Selenium (Se), Gallium (Ga), Arsenide, Zinc Selenide, Lead Telluride
• Silicon is mostly used.
• The foundation of modern electronics includes radio, computers, telephones, and many other devices.

Biomaterials

• Biomaterials are used in the human body to replace diseased or damaged parts.
• They do not produce toxic substances and must be compatible with body tissues.
• Can be produced in nature or synthesized in a lab using chemical approaches
• Can be metallic or ceramic.
• Used for joint replacement, bone plates & cement, artificial ligaments and tendons, heart valves, and artificial tissues.

Nanoengineered Materials

• These have a single unit size (one dimension) between 1 and 1000 nm, but usually 1-100 nm.
• These have unique optical, electronic, and mechanical properties.
• The use is to develop mechanical, electrical, magnetic, and other properties non-achievable otherwise
• Originates from "nanotechnology" with "nano" meaning structural entities on the nanometer (less than 100 nm).