Need a definition for cemented carbides...

[Streibig]

Freinds:

I am no metalurgist and I am struggling with a way to define cemented carbides as a group e.g. tungten carbide, etc. Is there a commonly recogogized denominator, between a tungten carbide and cerbide? I would appreciate any direction or advise anyone could provide me.

thanks,

Dan Streibig

 

[metengr]

If you are looking for the definition of what constitutes cemented carbides, here is a good description;

http://www.azom.com/details.asp?ArticleID=169

Typically, a carbide is a compound that is formed between one or more carbon atoms and one or more metal atoms - like tungsten carbide (WC) or iron carbide (Fe3C), etc. Once formed, they are normally very hard, and brittle compounds. Some carbides, depending on lattice structure, can be classified as ceramics.

 

[TVP]

ASM Handbook Volume 2 uses the following distinctions:

Cemented carbide: belong to a class of hard, wear-resistant, refractory materials in which the hard carbide particles are bound together, or cemented, by a soft and ductile metal binder. The authors (from Kennametal) limited the article to tungsten carbide cobalt-based materials.

Metal-bonded titanium carbide materials and steel-bonded tungsten carbide are part of the cermet category. Cermet is described as an acronym that is used worldwide to designate a heterogeneous combination of metal(s) or alloy(s) with one or more ceramic phases in which the latter constitutes approximately 15 to 85% by volume and in which there is relatively little solubility between metallic and ceramic phases at the preparation temperature.

Ceramics are defined as any of a class of inorganic, nonmetallic products which are subject to a high temperature during manufacture or use. Typically, but not exclusively, a ceramic is a metal oxide, boride, carbide, or a mixture or compound of such materials; that is, they include anions that play important roles in atomic structures and properties. This definition of ceramic components could be broadened to include nitrides, carbonitrides, and silicides.

 

[tomwalz]

I believe Cerbide is a tradename for a “binderless” cemented tungsten carbide. What is commonly called tungsten carbide is actually tungsten carbide grains cemented with metal such as cobalt, carbide, nickel, etc. The metal binder gives a great deal of strength but wears rapidly and is subject to corrosive attack.

By eliminating the binder you get a material with much greater wear properties which can work especially well in very low impact applications such as nozzles.

It is my understanding (might be correct, might not but I think I am pretty close) that binderless carbide is actually cemented carbide with a very low binder content.

So Cerbide is actually a cemented carbide.

Tom Walz

 

[Streibig]

Gentlemen,

Thank you for your advice! This appears to be exactly what I need. Now to finish my project writeup...

Cheers,

Dan