I.-HISTORICAL-PERSPECTIVE-OF-MATERIAL-SCIENCE

Historical Perspective of Material Science

  • Overview of the evolution of materials used by humans throughout history.

Three Ages System

  • The Stone Age (6000 BC)

  • The Bronze Age (2500 BC)

  • The Iron Age (1200 BC)

Beginning of Material Science

  • Start of the Stone Age, roughly two million years ago, marked the beginning of tool-making from stone.

Key Historical Events

  • Roman Invasion (55 BC)

  • Battle of Hastings (1066)

  • Henry VIII of England (1509)

  • World War II (1939)

The Stone Age Overview

  • Early Stone Age tools included basic implements like hand axes, scrapers, and knives, made from a variety of stone materials.

Types of Tools Used in the Stone Age

  • Hand Axes

    • Function: Cutting, scavenging, possibly hunting.

    • Common tool of the Stone Age. Oldest tool in human history.

  • Scrapers

    • Purpose: Chipped stone tools with a sharp edge used for processing hides to make leather.

  • Knives

    • Made from flint, used for cooking, hunting, and other cutting tasks. Common biface tools.

  • Awls

    • Sharp tools for punching holes in wood/leather, made from stone or bone.

  • Adzes

    • Hand tools for cutting and shaping wood, also used in making canoes and other wooden items.

The Three Stone Ages

  • Palaeolithic

    • Nomadic lifestyle; utilized local resources for food and tools.

    • Main diet: animal meat, fruits, and plants.

  • Mesolithic

    • Climate changes caused Britain to become an island; people followed animal herds.

    • Small groups of 10-40 people, utilizing the best flint for tool making.

  • Neolithic

    • Transition to permanent settlements; development of agriculture and domestication of animals.

    • Significant deforestation to create farmland; continued use of flint tools.

The Bronze Age (2500 BC)

  • Transition from stone tools to metal tools, primarily bronze.

  • Notable advancements: invention of the wheel, ox-drawn plow, and written language.

  • Agricultural practices expanded; creation of ornate objects and active trade.

  • Ended around 1200 BC with the onset of the Iron Age.

The Iron Age (1200 BC)

  • Marked by the widespread use of iron and steel, facilitating the production of stronger and cheaper tools.

Properties of Materials

  • Understanding material behaviors under stress is fundamental for various applications.

Mechanical Properties

  • Toughness: Energy absorption before breaking. Example: Rubber.

  • Hardness: Resistance to scratching and localized pressure. Example: Diamond.

  • Malleability: Ability to change shape without breaking. Example: Metals like gold and silver.

  • Density: Measurement of mass per volume. Example: Air is low density.

Electrical Properties

  • Describes material behavior in electric and magnetic fields; includes conductivity and resistance.

  • Conductors: e.g., Copper, Silver, Gold.

  • Insulators: e.g., Rubber, Glass.

  • Semiconductors: Unique properties allowing for varying levels of conductivity under different circumstances.

Magnetic Properties

  • Diamagnetism: Materials repelled by magnetic forces.

  • Paramagnetism: Attraction to magnetic fields.

  • Ferromagnetism: Strong attraction and potential for permanent magnetism.

Thermal Properties

  • Understanding how materials respond to heat; important for applications in cookware and thermal insulation.

Optical Properties

  • How materials interact with light, incorporating reflection, refraction, and absorption.

Classification of Materials

  • By Origin:

    • Natural Materials: Derived from nature (e.g., wood, stone).

    • Artificial Materials: Man-made, often combining or modifying natural substances (e.g., plastics, metals).

  • By Composition and Properties:

    • Metals: High electrical and thermal conductivity (e.g., Iron, Aluminum).

    • Polymers (Plastics): Lightweight and versatile (e.g., Polyethylene, Nylon).

    • Ceramics: Inorganic materials for construction and electronics.

    • Composites: Two or more distinct materials to enhance properties.

Advanced and Modern Materials

  • Advanced Materials: Engineered for specific properties exceeding traditional materials; impactful across industries.

  • Modern Materials: Recently developed or refined materials, though not necessarily exhibiting exceptional performance.

  • Examples of advanced/modern materials include:

    • Carbon Fiber: Used in aerospace for lightweight strength.

    • Kevlar: High strength for protective gear.

    • Shape Memory Alloys: Retain original shapes when heated.

    • Nanomaterials: Coatings and various applications.

    • Gore-Tex: Breathable, waterproof textiles.