How Inserts are made?

[Wiseco]

I have done some search without success so here I am.

Does anyone knows how inserts are made? Where can we find information on that?

Lets debate on that.

[Switcher]

Not sure how they make inserts (prob. press them?).

I do know that Warren Buffett owns Iscar ($4 billion)!

.

[Wiseco]

I ever heard that a part of the making process is something like baking. I saw in the Iscar tool that they use an autoclave or something like that...

[One of Many]

I had heard a few of the processes involved powdered metal presses. Where in specially treated powdered carbide is deposited into a mold/die similar to an injection mold type of die(the cavity is pointed up). The powder is then pressed under high pressure between the 2 dies. The baking process may only complete the binding.

Then I'd expect, it is only a matter of coating and/or feeding them into a grinder if need be.

DC

[Geof]

Inserts are made by sintering, that is why they are sometimes called sintered carbide.

The full name for carbide is tungsten carbide, it is a chemical compound made by reacting carbon and tungsten at high temperature. Tungsten carbide has a very high melting point so it is not possible to melt it and cast it into the shape for inserts which is why the sintering process is used.

Sintering takes a very fine tungsten carbide powder, there may be other things added I don't know, and the powder is compressed at very high pressure and high temperature in a die. The pressure and temperature combined causes the powder to fuse together where it is touching so it becomes a solid. It is not a solid solid, because it is made of powder that only touches over small areas there are very tiny voids but they are very tiny; with micrograin carbide very very very tiny. But they are there and the powder particles are there as little lumps which is why a carbide tool cannot be sharpened to the same extremely fine sharp edge as is possible with high speed steel.

Sintering is also used to make powdered metal items; gears, sintered bronze bushings and many small metal shapes that are made in large quantity.

[dpuch]

Some more information: http://en.wikipedia.org/wiki/Tungsten_carbide

Which also mentions that cobalt or chromium is usually used as a binder/filler for the small voids Geof mentioned.

http://www.freepatentsonline.com/5281260.html
http://www.freepatentsonline.com/4684405.html
and
http://www.precisionballs.com/tungsten-carbide.htm

[cdlenterprises]

Huh.....I thought the insert fairy dropped new inserts on your bench every night when you leave....

[ajl6549]

Geof is correct, with one exception, today we have "sub-micron grade" carbide which is made from sub-micron sized particals etc. This allows for grinding very sharp edges and TRS (transvers rupture strengh) ratings higher than that of HSS. It also allows it to be pressed into very intricate shaps etc.

[ajl6549]

Originally Posted by cdlenterprises Huh.....I thought the insert fairy dropped new inserts on your bench every night when you leave....

That is exactly what happens but our fairy's name is Iscar and he also drops off an invoice with really big numbers on it

[Wiseco]

Okay! Thanx for the info Geof!

[kalmah]

Originally Posted by Wiseco I have done some search without success so here I am. Does anyone knows how inserts are made? Where can we find information on that? Lets debate on that.

I can give you some information.

1) The WC powder and the cobalt powder with other elements are mixed. After the mix the powder should be homogenous.
2) The mix is injected to a insert die. After that, the insert looks like "chalk"
3) THe insert is sintered in a sintering furnace by HIP process. After the sintering the insert has is final structure. It's cemented carbide
4) The final geometry is obtained by grinding
5) If the insert don't need coating, it's washed and packed.
6) If the insert need a coating, there is two method CVD coating and PVD coating.
The PVD coating is more expensive that CVD coating, but the coating is "smoother". The method for coating is the following:
- I) Vacuum in the coating chamber
- II) The argon ions (positive) are put in the coating chamber. The target is negative. With the voltage, the ions hit the target (Ex: Titanium) and the atoms of target react with a gas (Nitrogen, Carbon) and after it's deposited on the cutting tool.

The CVD coating is cheap but the coating is "rough"
- I) Vacuum in the coating chamber
- II) Two gas, which don't react at ambiant temperature are put in the coating chamber
- III) The cutting tool are heated at 800-1000°C and the gas react between us. THe first reaction product (ex: Al2O3) is deposited on the cutting tool surface and the second reaction product is ejected outside the coating chamber and it's often very toxic and absolutely not ecological !!

[Wiseco]

I was sure it had an injection part in that!

Thanx!