| What
are Surface Characteristics? |
| Surface
Area... |
| |
|
- As
particle size decreases, the specific surface area (m2/gram)
increases.
- As
surface area increases, so does the powder’s ability to
retain or adsorb foreign material.
Area represented
by 1 carat of powder: |
 |
|
|
0.1um
(10m2/ct)
|
|
1um
(1m2/ct)
|
|
10um
(0.1m2/ct)
|
| For
fine-size particles surface effects dominate and control behavior.
|
| |
| Surface
Chemistry... |
| |
How
"clean" is the powder?
- Levels of inclusions/catalyst at surface.
- Levels of residual ions from processing.
- Moisture content.
- Degree of oxidation.
- Coated surface characteristics.
- Particulate contamination. |
 |
|
"Clean"
Surface
|
 |
Surface
chemistry affects:
- Wetting (in water, with bond materials).
- Dispersion stability.
- Flowability/mixability.
- Susceptibilty to static charge.
- Plating characteristics.
- Bond reactivity. |
Contaminated
Surface
|
| |
| |
| Surface
Measurements... |
| |
| Surface
Area- Nitrogen Adsorption; Devices-Micrometrics Flowsorb |
| Residual
Ions- Atomic Absorption ; Devices- Inductively Coupled
Plasma |
| Moisture
Content- Thermogravimetric; Devices- Thermogravimetric
Analyzer |
| Degree
of Oxidation- Gas Fusion; Devices- LECO Oxygen Detector |
| Particulate-
X-ray Fluorescence; Devices- Scanning Electron Microscope
with EDAX detector. |
| Conventional-
Titration methods, gravimetric techniques. |
| |
|
GE's
measurement capability ensures control and consistency.
|
