Re: Tungsten carbide

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>

Malcolm, Terry, All
I wonder if there is a difference in the carbide used for cutters and
inserts that that are "indexed" or set screwed in place, and the carbide
that is meant to be soldered?
I use mostly tool type, small end mills, inserts with a hole in the
center for screwing in place or made for a set screw mount.
These all seem to work well with no erosion and they all do seem shiny.
I tried a small static gap once using nitride coated inserts, "these do
not work" at all! they just will not arc very well, almost like no tank
capacitor in circuit when there is??
The carbide that is meant to be soldered onto a holder, or shank, does
seem to sharpen much easier on a green wheel. I tried flattening out a
carbide shank from an end mill i snapped off, It would barely scratch
the break, but the flat gray squares that i have will grind pretty
smoothly. these are precut for brazing onto boring bar shanks. I did a
little test and used a 1" diamond shaped insert to try to scratch the
braze on stuff, it did scratch so the inserts are harder then the
("tips, caps, or whatever")?

If someone wants to carbide face some brass rod for a gap, but they
don't want to braze them, They should look around for some round inserts
with the center hole for mounting. these come in all shapes and sizes so
chances are good for a match.

I like to get the 1/4" - 1/2" boring bars or end mills if i'm looking
for rod stock.
Most machine shops will have a good selection of dull cutters, But i
think carbide scrap price is on the rise so it could be scrapped more
often now?
I've gotten 1/32" - 1/2" rod in three to four inch lengths that were
used to zero out comparaters with so it is around.
It would be nice to get some more precise information about carbide, but
i haven't found any as yet?
It would be interesting to try some carbide in a poulsen arc or furnace
type arc, then give it a thorough testing? maybe the molecular structure
after such high stress on the metal would be nice? Either way, I have
yet to see any carbide melt in the heat of an arc, I have noticed that
tungsten welding rod does melt or erode over time but the carbide
doesn't seem to?
Take care,
Marc M.


Tesla list wrote:
> 
> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> 
> Hi Malcolm,
> 
> The carbides that look like shiny metallics seem to be fine.  Avoid the
> gray dull looking kind.  They seem more ceramic than metal.  the all look
> fine with an ohmmeter but arc travel just on the surface of the gray stuff.
> 
> Cheers,
> 
>         Terry
> 
> At 08:53 AM 9/24/2001 +1200, you wrote:
> >Hi all,
> >        As I've said in the past, I've had excellent results with
> >tungsten carbide. I'm amazed to see there are so many different
> >"flavours" available. So what type do I use I hear you ask? Well, I
> >get my gap electrodes made by a local toolmaker who carries some
> >stock, presumably for making cutting tools. I know it will be pretty
> >hard stuff. I will ring them later and if I can find out which type
> >they use, I'll post to the list.
> >
> >Malcolm
> >
> >
> >On 22 Sep 2001, at 22:07, Tesla list wrote:
> >
> >> Original poster: "brian by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> ><ka1bbg1-at-mcttelecom-dot-com>
> >>
> >> Hi, also some of the powder mixes are sometimes coated with exotic
materials
> >> as a particle coat and when melted(sintered and pressed) that material now
> >> adds another propietary mix surely not to be announced.
> >> i do know if it was made by Tan-Tung then it will have tantalum and
tungsten
> >> mixture and few other materials. tan-tung usually isnt magnetic(the way i
> >> find tan-tung cutting tools) when mixed with other tool steels. it
also cost
> >> substantially more. There are more TCarbide mixes than we realize,
most are
> >> propietary,there must be 1,000's of recipies. cul Brian f.
> >> ----- Original Message -----
> >> From: "Tesla list" <tesla-at-pupman-dot-com>
> >> To: <tesla-at-pupman-dot-com>
> >> Sent: Friday, September 21, 2001 2:34 PM
> >> Subject: Tungsten carbide
> >>
> >>
> >> > Original poster: "Luc by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> >> <ludev-at-videotron.ca>
> >> >
> >> > Hi Terry, Marc, list,
> >> >
> >> > May be I have an explanation other than solder diffusion of why
> >> > some have good success with tungsten carbide electrode and some
> >> > have poor result ( erosion ).
> >> >
> >> > TC are kind of ceramic composed of a variety of different
> >> > material and proportion of TC content vary from 98% to as low as
> >> > 60%. Some used titanium carbide as addition, from what I know
> >> > titanium have poor reaction to arc.
> >> >
> >> > In conclusion TC are made of WC, Ni, Co, Cu, TiC, Fe, etc. in
> >> > different ratio.
> >> >
> >> > See these link:
> >> >
> >> > http://www.generalcarbide-dot-com/grades/
> >> >
> >> > http://www.chinatungsten-dot-com/ctcgp.htm
> >> >
> >> > http://www.leechcarbide-dot-com/grade.htm
> >> >
> >> > The question is what is the best grade of TC can be use as
> >> > electrode? What is the best binder; nickel or cobalt? What
> >> > proportion of WC is the best? Probably the higher, other material
> >> > are added mostly for lowering the brittelness of the TC.
> >> >
> >> > I think the question could be ask to an association of mfr. of
> >> > TC, I'm sure one of you with a better english writing ability
> >> > than me  could write to them, I think of a kind of list of the
> >> > best grade to the worst because may be the kind of shape we need
> >> > for electrode are not produced with the best grade for resistance
> >> > to arc erosion.
> >> >
> >> > Cheers,
> >> >
> >> > Luc Benard
> >> >
> >> >
> >> >
> >>
> >>
> >>
> >>
> >
> >