Materials Science and Engineering Chapter 1 Review

Flashcards covering the foundational concepts of materials science, including history, material types, property definitions, and structure relationships.

BCE

Before Common Era.

Earth's Crust Abundance: Oxygen

The most abundant element in the Earth's crust, making up $46.1\%$ by weight.

Earth's Crust Abundance: Silicon

The second most abundant element in the Earth's crust, making up $28.2\%$ by weight.

Stone Age

Period beginning around $300,000\,BC$ where people lived in caves and hunted with stone-made weapons.

Copper Discovery

Occurred between $8600-6800\,BCE$ in a Neolithic settlement in southeastern Turkey; it was the first metal discovered and cold hammered.

Bronze Age

Period beginning around $3000\,BC$ characterized by the mixing of metals, specifically Copper and Zinc.

Iron Discovery

Occurred around $1500\,BCE$, creating a revolution in warfare and cultivation.

Sir Humphrey Davy

Isolated Magnesium for the first time in $1808\,AD$ in London, England.

Hans Christian Orsted

First isolated Aluminum in $1825\,AD$ in Copenhagen.

Hall Process

The process established in $1886$ for the extraction of Aluminum from Alumina ($Al_2O_3$).

Metals

Materials characterized by atoms in regularly defined, repeating positions (crystals) and "free electrons" that make them good electrical conductors.

Ceramics

A combination of metallic and non-metallic atoms that are often crystalline, high temperature stable, and brittle.

Polymers

Long chain molecules with repeating groups characterized by low density and low strength.

Composites

A combination of two or more materials, used in structural applications where rigidity, strength, and low density are critical.

Semiconductors

Materials such as Silicon, Germanium, and $GaAs$ used in electronic and optical devices with mechanical properties similar to ceramics.

Intensive Properties

Material properties that do not depend on the amount of the material, such as density or strength.

Microstructure

The organization of a material at the atomic, granular, and electronic levels, determining where every atom is in relation to others.

Alloy

A homogeneous solid solution or mixture of two or more elements (at least one of which must be a metal) where one usually dissolves atomistically in the other.

Structure-Property-Process Relationship

The principle that properties are governed by atomic bonding and microstructure, which are derived from how the material is processed.

Microstructure-Insensitive Properties

Properties that typically do not change based on structural details, including Elastic Modulus, Thermal Coefficient of Expansion (TCE), and Specific Gravity.

Microstructure-Sensitive Properties

Properties that change based on internal structure, including Yield Strength, Thermal Conductivity, Electrical Resistivity, and Fracture Toughness.

Elastic Modulus (Young Modulus)

The ratio of stress to strain, represented by the formula $E = \frac{\sigma}{\epsilon}$, or the slope of the load vs. deformation curve before plastic deformation.

Ductility

The ability or extent of a material to deform plastically.

Brittle

A characteristic of materials that show little or no plastic deformation before breaking.

Strength

The maximum engineering stress that a material can withstand.

Crystalline

A material characterized by atomic and/or molecular periodicity.

Amorphous

A material characterized by a random distribution of atoms and molecules.

Fracture Toughness

The amount of energy a material absorbs until it fractures.

Yield Strength ($\sigma_y$)

The stress level at which a material begins to deform plastically.

Ultimate Tensile Strength ($\sigma_{uts}$)

The maximum stress that a material can withstand while being stretched or pulled before necking.