Definitions

Question 1

Coefficient of thermal Expansion

Answer 1

The rate at which a material expands with increase in temperature with constant pressure

Question 2

Covalent Bond

Answer 2

A type of atomic bond characterized by the sharing of an electron pair between the two atoms

Question 3

Ductile

Answer 3

A material’s ability to bend without breaking

Question 4

Anion

Answer 4

A negatively charged ion (would be attracted to the anode [the positively charged electrode] in electrolysis)

Question 5

Martensite

Answer 5

A very hard form of steel that is formed when austenite is cooled very rapidly

Question 6

Eutectoid

Answer 6

When a singular solid phase cools into two other solid phases at the same time

Question 7

Ohm’s Law

Answer 7

V=IR, voltage, current, resistance

Question 8

Isostress

Answer 8

A condition of constant stress

Question 9

Pearlite

Answer 9

The combination of alpha ferrite and cementite

Question 10

FCC

Answer 10

Face Centered Cubic, can hold 4 atoms per unit cell with a lattice constant of a = 2rsqrt(2)

Question 11

Hardness

Answer 11

A material’s resistance to scratching, cutting, or abrasion.

Question 12

Toughness

Answer 12

A material’s ability to withstand stress without fracturing (only deforming plastically)

Question 13

Poisson’s Ratio

Answer 13

The ratio of how much something will get longer whenever you apply a force perpendicular to that

Question 14

Bainite

Answer 14

Bainite is a microstructure of steel that forms when steel is cooled slower than is required to make martensite but faster than will make pearlite

Question 15

Thermoplastic

Answer 15

A polymer that becomes moldable at a higher temperature and hardens as it cools. This must be repeatable

Question 16

Cathodic Protection

Answer 16

A technique used to reduce corrosion of a metal surface by making it the cathode of an electrochemical cell

Question 17

Tempering

Answer 17

To improve the hardness and elasticity of a metal by reheating it and then cooling it.

Question 18

Phase

Answer 18

A region of material that is chemically uniform and physically distinct

Question 19

Creep

Answer 19

Time-dependent deformation at elevated temperature and constant stress

Question 20

Eutectic

Answer 20

When a liquid phase solidifies into two solid phases. Also the lowest possible melting point

Question 21

HCP

Answer 21

Hexagonal-Close-Packed, a unit cell that has 6 atoms per unit cell, and a coordination number of 12

Question 22

Transistor

Answer 22

A linear semiconductor that can control a larger current using a much smaller current

Question 23

Forward Bias

Answer 23

A PN junction has a forward bias when current is being applied from p –> n

Question 24

Flux

Answer 24

An effect that passes through a material or a substance

Question 25

Ceramics

Answer 25

Brittle compounds that have a high melting temperature and are very insulative

Question 26

Constructive interferance

Answer 26

When two waves meet in such a way where their amplitudes add to each other

Question 27

Thermal conductivity

Answer 27

A material's ability to conduct heat

Question 28

Van der Waals bonds

Answer 28

The bonds form because charge is not evenly distributed in a molecule. Molecules can be slightly polar, and so they attract other molecules

Question 29

True stress

Answer 29

The applied load divided by the actual cross-sectional area of the specimen

Question 30

Scanning electron microscopy

Answer 30

A type of microscope that uses the scattering of a concentrated beam of electrons to image the topography of a material

Question 31

Atomic packing factor

Answer 31

How many atoms fit in one unit cell

Question 32

Hume-Rothery rules

Answer 32

For substitutional solid solutions: 1. The atomic radii must be no more than 15% different 2. The crystal structures must be similar 3. The solute and solvent should have similar electronegativity 4. same valency

Question 33

MOSFET

Answer 33

An integrated circuit that uses semiconductors with a thin layer of silicon dioxide between the gate and channel

Question 34

Atomic Number

Answer 34

The number of protons in an atom

Question 35

Allotropes

Answer 35

When an element can exist in two or more different forms, like carbon can be graphite, charcoal, or diamond.

Question 36

Galvanizing

Answer 36

Coating a metal with a protective layer of zinc to prevent rusting.

Question 37

Resolution

Answer 37

The smallest distance between two points on a specimen that can still be distinguished as two separate entities

Question 38

Pitting corrosion

Answer 38

Localized corrosion where small holes/cavities are formed in the metal

Question 39

Dislocation

Answer 39

A crystallographic defect or irregularity within a crystal structure.