Flashcards in Lectures 4-7 Deck (23)
The property of a material that enables it to resist plastic deformation, penetration, indentation and scratching.
A scale using minerals which increasing with hardness
What are the three hardness test?
Brinell, Vickers and Rockwell
-Static load, 100-3000kgf
-Ball diameter, 1-10mm
Dwell time, 10-30 seconds
How do you calculate and write Brinell's number?
BH=force/impression of indentation
Dwell time 10-15s
a diamond with an edge at 136 degrees
VH calculation and number?
VH=force/surface area of impression
Major:60, 100 and 150kgf
Uses a minor load to cause an indentation and then the major load is added to make an impression.
Specific heat capacity
The amount of energy used to change the temperature of an object per unit mass
c=secifitic heat capacity
How to calculate the linear heat coefficient of thermal expansion?
-ε=a*change in temperature
a=change in length/ original length*change in temperature
How does the linear, area, and volume coefficient to thermal expansion change with each dimension?
(what the equation?)
Change in length=a*change in temperature
Change in area=2a*change in temperature
Change in volume3a*change in temperature
heat flux=thermal conductivity/temperature gradient
σ=Ea*change in temperature
A three-dimensional array of points with the identical surrounding.
The smallest repetitive volume which contains the complete lattice pattern of the crystal.
Four in cube
four in a cube with one in the middle
four in a cube, with one in between each cube.
what are the four-point defects
-Small substitution atom
-Large substitution atom
Dislocation: screw and edge
produce permanent plastic deformation
Are the 2D representation of the material.
Effects conductivity and strength of an object
A system consisting of two materials
Gibbs phase rule
C=number of components
F=number of phases that coexist
-For constant pressures
The Lever Rule
-Shows the amount of liquid to solid ratio.
R=ratio of liquid
Q=ratio of solid