Tungsten Carbide and Cermet, Some Basic Facts
Tungsten Carbide and Cermet, Some Basic Facts
Cermet stands for metal based ceramic. Thus tungsten carbide is technically a cermet. The way I got the story was that ‘Cermet’ came to mean titanium nitride, titanium carbonitride or similar was due to a translation error. An American asked a Japanese what the new material was called and the Japanese said that it was a cermet. Because it was a titanium based material the term cermet came to be used for titanium based materials.
The language in this industry is often very imprecise. A great many manufacturers are now and have always been extremely reluctant to share any technical data. I too have heard, as has CarbideBob, that the MG 18 grade is 10% cobalt. Lately I have heard that it is 20% cobalt.
There’ve been huge advances in the tungsten carbide and cutting tool tip industry in the three decades I have been in it. This is especially true in the last decade.
As part of our work on filtering coolant we got peripherally involved in plants for the manufacturing of computer chips. In these operations they measure contamination in terms of individual atoms. A single sulfur atom can ruin a transistor or similar device.
This necessity to make ultrapure materials created the technology to make ultrapure materials which has been adapted into the tungsten carbide industry.
Tungsten, carbon and cobalt powders are just a start. There is quite a variety of other metals that are added to control grain growth, to change the characteristics of the binder and otherwise improve the materials.
The powders are incredibly fine and hard to work with. If you’ve ever had to work with toner powder you’ll understand. A big advancement has been spray drying which creates ultrafine powders and makes them more mixable.
Cutting steel with carbide
If you look at it from a certain standpoint you really don’t cut steel. Rather you could consider it that the process of cutting steel is actually more a scraping action. This makes more sense if you consider that steel is a homogenous material and compare that to something, such as wood, which is a heterogenous material. Wood is a bundle of individual fibers that have to be actually severed.
There were some excellent discussions above about edge prep. As near as I can tell, much of what look like disagreements was actually accurate information about differing methods.
Then, again, the term carbide covers a huge range of individual grades.
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