Characterization Flashcards
If you are given the percentage of theoretical density? How do you find the porosity?
What’s not TD is porosity so its the other percentage to get 100
What is % total porosity?
open + close
(extra) If you have to choose to use the 3-point or 4-point bending test, which one?
4-point because of the positions of the stresses
When an incident beam is shined at a sample, what are the three types of electrons that go through the sample? What do you learn from them?
- Elastically scattered electrons
- structural analysis & HR imaging
- Transmitted electrons
- morphological info
- Inelastically scattered electrons
- composition and bond states
When an incident beam is shined at a sample, what are the 5 types of electrons/matter that are “reflected”?
- angular electrons
- x-rays
- primary backscattered electrons
- cathodoluminescence
- secondary electrons
What are the 7 different types of particle size distribution measuring techniques?
MSSCPRL
Mari says Sarina cries pretty rarely lately
Microscopy
Sieving
Sedimentation
Centrifugation
Permeation
Resistive Pulse
Light scattering
What is X-Ray diffraction?
The powder diffraction method used to identify the phases present & types of crystals in a material
What condition do X-Ray Diffraction beams have to satisfy? Why?
Bragg’s Law/condition
Because materials/powders are composed of numerous randomly oriented grains, the diffracted beams are produced from all crystalline planes that satisfy the law
What is Bragg’s Law?
How do incoming X-rays interact with crystal planes?
they diffract from crystal planes
How do you compute the planar spacing, d with X-ray diffraction?
- measure the critical angle
- plug into the formula
What is intensity measured as a function of in X-Ray diffraction?
of angle theta
What do the angles where the peak in intensity occurs in X-Ray diffraction correspond to?
A unique set of crystalline planes
What is a result of X-Ray diffraction and how is it compared?
A unique set of theta values results, which are compared to the known theta values from material standards
What would the XRD pattern look like of a crystalline vs. amorphous material?
What are two dif types of TEM?
Bright field imaging and off-axis dark field
What kind of samples does TEM require?
Very thin ones
What are two ways to measure density? What are they good for? What are their characteristics?
Gas Pycnometry and Archimedes’ method
Gas:
- for powders
- based on Boyle’s law
Archimedes’
- for pieces
- % of theoretical density
- allow to calculate porosity
- ASTM method