View allAll Photos Tagged graphite
Graphite on Paper
One of my first drawings. 2002.
done from a photo- I would give credit, however it was a long time ago and I don't remember where I found the photo.
Testing the macro capabilities of a Canon EF-S Kit 55 - 250mm f/4.0 - 5.6 IS Lens @ 250mm. Nothing exceptional, but this shot came out looking nice.
Currently working on this! The mountains are shaping up to be pretty good, now only for the foreground...
reference photo : 1x.com/photos/nature/26475/
sketch: www.flickr.com/photos/vanesa-mercado/3981678205/in/set-72...
DoITPoMS, University of Cambridge
The fused alumina ceramic grain and natural graphite flakes (seen edge on in the micrograph) are held together by a polymer-derived carbon bond and protected from oxidation by a metal (bright Si) which betters oxygen in use to form e.g. SiO2. A true composite material.
System
Al2O3-C-Si
Composition
Al2O3, C up to 30 (wt%), Si few%
Reaction
Processing
Powders and flake graphite mixed and granulated with phenolic resin or pitch binder. Heated <400 °C to decompose binder leaving behind a fine C bond. Antioxidising additives (e.g. Al, Si, SiC, B4C) used to protect the C and graphite flakes. Granulated mix is hot isostatically pressed and fired in reducing atmosphere.
Applications
Hollow-ware for steel continuous casting e.g. submerged entry nozzles and shrouds and sliding gate valves.
Sample preparation
Polished but unetched.
Technique
Reflected light microscopy
Length bar
TBC
Contributor
Prof W E Lee
Organisation
Department of Engineering Materials, University of Sheffield