What ceramic materials are available for cermet saw blades?
The cermets we sell are TiCN and are a cemented material. Cermet saw tips are TiCN (Titanium Carbonitride). The Cermets are composed entirely of TiC (Titanium Carbide) and TiN (Titanium Nitride). These are the same materials used to coat ordinary grades of carbide to make them more wear resistant. A cermet is not coated instead it is solid coating material. Although the US Patent Office accepts this as a ceramic it is best here to consider it as an intermediate grade between tungsten carbide and true ceramics such as Alumina, Silicon Carbide, Zirconia materials and similar. It has a lot of the good qualities of true ceramics as well as an acceptable transverse rupture strength of over 200,000 pi. Alumina and other materials are also available for these applications.
Why are cermet saw blades so expensive?
As the volume grows the price will drop like a rock. With increasing demand, the amount of cermet material treated will increase and the cost of treating cermet tips will approach that for treating carbide materials. It will be a while but eventually we will be treating tips for pennies instead of dollars and some tips we will treat for fractions of a cent.
Now we have to buy minimum quantities, which are usually 3,000 to 5,000 parts in order to sell a hundred or so.
We are treating the parts on a laboratory basis. It takes an engineer about an hour to set up to treat the parts and about 45 minutes to run a pound or so, which equates to at least an hour to run between 100 and 500 parts. This is high cost labour and laboratory time which currently needs to be re-couped in the price of the parts.
Finally, we use small quantities of uncommon, high purity chemicals. Again cost is very high because there is a very small demand. Apparently we are the only people using some of these chemicals commercially.
Even with a high tip price it only costs about 30% more to make a cermet tipped saw. The customer gets 4 times the performance and five times the life so they are willing to pay twice as much for the saw.
Cermet tipped saws typically need about 1/3 fewer tips so that really helps with the cost also.
How are ceramic tips attached to the metal blades?
You can make a cermet tipped saw the same way you make a carbide tipped saw. When we treat them they braze the same. Some really good brazers say they notice a difference. We don’t see that when we do them but there are ‘hands on’ brazers much more experienced than we are. In any case you can use a torch, induction or most other commonly available processes.
How are ceramic tips ground?
You can use any good quality grinder. It must be a sturdy, rigid machine. Cermets are much more wear resistant than carbide so they are harder to grind.
You need a different set of diamond wheels. If you use carbide wheels to grind cermets they will grind them but there will be a huge amount of rubbing action and a lot of heat that will thermally stress the cermets.
You also need to grind about half as fast. We suggest that you grind to an edge that looks chip free at 30-power magnification. When you are through grinding you need to take a fine hone and lightly hone the edges. We recommend at least 400 grit.
Cermet edges can get much sharper than carbide. They can get so sharp that they are thin enough to chip easily. Once they chip they are rapidly destroyed. If you hone the edge you can prevent chipping and the cermets then run beautifully for many times as long as carbide.
What is the future for ceramic tipped saw blades?
Ceramics will largely replace tungsten carbide as tungsten carbide has largely replaced steel. Currently, the objections are the price of the material, the fact that it is hard to make and hard to use. You also hear objections because there is no market for it yet and there are few machines that can take advantages of all of its benefits. These are identical to the reasons people used to explain why carbide couldn't work.
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