The formation of transition metal nitrides is reviewed critically with special reference to newer production mechods and fabrication techniques. Crystal structures and types of bonding arc dircussed in relation to those of other nitrides and refractory hard metals generally, of borides, carbides and silicides. Information so far available on the sintering of materials is summarised for nitrides (as with borides and carbides), the sintering is influenced by additives and impurities such as oxides formed by partial hydrolysis and oxidation. Resistance to oxidation is increased by sintering and hot-pressing the refractories. is formed to give stable oxide layers. The sintering of the oxides is controlled by surface diffusion promoting grain-boundary penetration at lower temperatures (above about 1/3 mp oxide in k) and crystal lattice diffusion at higher temperatures (above Tammann Temperature, about 1/2 mp oxide in K). Comparison of the oxidation of nitrided and free metals indicates that oxide sintering i s inhibited sometimes by removal of nitrogen but accelerated occasionally by the remaining metal.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:580421 |
| Date | January 1970 |
| Creators | Ali, Irshad |
| Publisher | University of Plymouth |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10026.1/1878 |
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