Attila Kinali

Some of the best piezoelectric transducers are made from sintered ceramics. Crystalline salts were once used, but they are highly hygroscopic. -Chuck Harris Attila Kinali wrote: > On Fri, 07 Apr 2017 21:30:56 +0200 > Rob Klein <rob.klein@smalldesign.nl> wrote: > >> In general, metrology equipment doesn't get thrown about much ... >> >> I know some calibrators have (heated) modules on ceramic substrates, so it's not that it is completely unheard of. >> > > So, in summary, if the right substrate is used, then it's very usefull? > > What about piezoelectricity? Is that a concern with the sintered substrates? > Or is that only a problem with mono-crystaline materials? > > Attila Kinali >

Hi Chuck, I can't talk about most of those applications but in the ones I know of the ceramics are used for their hardness (ie ability to withstand deformation). What we want is toughness which is a different thing (ability to withstand breaking). Compromising hardness and toughness is why in a knife you only harden the cutting edge, and you specifically watch out that the rest doesn't harden, or you even reverse the hardening process on that part. High hardness and low toughness is also why ceramic knives chip more easily than metal ones. I haven't seen fully ceramic gun parts, interesting idea. I know very little about gun parts. I wonder if it's just a layer over a metal. Brake linings will have the benefit of a tough backing which will enable load bearing. This is what you want from a pcb - toughness for load bearing, and minimal hardness for reduced fragility. I don't suppose lathe inserts will be made in the same way a pcb would be. If you know more please let me know, I'd love to hear more about it. And yeah, I like to break things when I can :) On Sun, 9 Apr 2017 18:37 Chuck Harris, <cfharris@erols.com> wrote: > Why exactly do you think ceramic is delicate? > > It is used to make knifes, pistols, internal combustion > engines, turbines, brake linings, clutches,... and even > insert tooling for machining very hard materials. > > It isn't your mother's teapot! > > Or, are you the proverbial "bull in a china shop" in > everything you do? > > -Chuck Harris > > cheater00 cheater00 wrote: > > Hi Rob, thanks for your email. > > > > My take is you want your standards and calibrated equipment to last very > > long due to increasing stability, and that is in direct opposition to > > making them out of fragile materials, even if they don't get thrown > around. > > Accidents happen, people trip over, this can't really be helped. I'm no > > metrology expert by any degree, it just seems to me that making it even > > easier to break your $250k box is a bad idea if it can be wholly avoided > by > > using a different material that'll meet requirements too. > > > > You're right that it's not unheard of - ceramics were even used in mobile > > testing equipment eg by tek - but they didn't know better back then, or > > they didn't care because equipment would be phased out before it had > chance > > to break. > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. >

There are modern ceramics that are among the toughest things you will ever see in your life. A ceramic gun is entirely of ceramic. There are automotive engines made entirely of ceramic. As are some turbines used in turbochargers for engines. One of the things that can make ceramic extremely tough is to put it in a mold, and compress it to many tons per square inch, while in the green state. After that, it is already tough. Then fire it to sinter everything together. Google is your friend. Again, it isn't your mother's teapot. -Chuck Harris cheater00 cheater00 wrote: > Hi Chuck, > I can't talk about most of those applications but in the ones I know of the > ceramics are used for their hardness (ie ability to withstand deformation). > What we want is toughness which is a different thing (ability to withstand > breaking). Compromising hardness and toughness is why in a knife you only > harden the cutting edge, and you specifically watch out that the rest > doesn't harden, or you even reverse the hardening process on that part. > High hardness and low toughness is also why ceramic knives chip more easily > than metal ones. I haven't seen fully ceramic gun parts, interesting idea. > I know very little about gun parts. I wonder if it's just a layer over a > metal. Brake linings will have the benefit of a tough backing which will > enable load bearing. This is what you want from a pcb - toughness for load > bearing, and minimal hardness for reduced fragility. I don't suppose lathe > inserts will be made in the same way a pcb would be. If you know more > please let me know, I'd love to hear more about it. And yeah, I like to > break things when I can :) > > On Sun, 9 Apr 2017 18:37 Chuck Harris, <cfharris@erols.com> wrote: > >> Why exactly do you think ceramic is delicate?

Interesting, good to know! I assume those materials were not available in the 70s and 80s? Hybrids from those decades are known to be very fragile. On Mon, 10 Apr 2017 04:08 Chuck Harris, <cfharris@erols.com> wrote: > There are modern ceramics that are among the toughest things you > will ever see in your life. > > A ceramic gun is entirely of ceramic. There are automotive > engines made entirely of ceramic. As are some turbines used > in turbochargers for engines. > > One of the things that can make ceramic extremely tough is > to put it in a mold, and compress it to many tons per square > inch, while in the green state. After that, it is already > tough. Then fire it to sinter everything together. > > Google is your friend. > > Again, it isn't your mother's teapot. > > -Chuck Harris > > cheater00 cheater00 wrote: > > Hi Chuck, > > I can't talk about most of those applications but in the ones I know of > the > > ceramics are used for their hardness (ie ability to withstand > deformation). > > What we want is toughness which is a different thing (ability to > withstand > > breaking). Compromising hardness and toughness is why in a knife you only > > harden the cutting edge, and you specifically watch out that the rest > > doesn't harden, or you even reverse the hardening process on that part. > > High hardness and low toughness is also why ceramic knives chip more > easily > > than metal ones. I haven't seen fully ceramic gun parts, interesting > idea. > > I know very little about gun parts. I wonder if it's just a layer over a > > metal. Brake linings will have the benefit of a tough backing which will > > enable load bearing. This is what you want from a pcb - toughness for > load > > bearing, and minimal hardness for reduced fragility. I don't suppose > lathe > > inserts will be made in the same way a pcb would be. If you know more > > please let me know, I'd love to hear more about it. And yeah, I like to > > break things when I can :) > > > > On Sun, 9 Apr 2017 18:37 Chuck Harris, <cfharris@erols.com> wrote: > > > >> Why exactly do you think ceramic is delicate? > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. >

Yes, there have been enhancements, but ceramics have been tough since long before the 70's and 80's. Think about the insulator on your common spark plug. The platinum variety are sitting out in an explosive inferno with no support. Think about your gob ordinary Corning Corell ceramic plate, or corning casserole dish. They get wacked around, and just take it. Sure, you can break them, but not through casual use. Ceramic hybrids have not been known to be very fragile by anyone I know. They can be tiny, and tiny things have problems when forced around by big clumsy things. They certainly would be more fragile made from an equivalent dimensioned piece of FR4. FR4 would flex, breaking all of the thin film printed resistors, and traces. Ceramic won't flex, which is largely why it is used in hybrid circuitry. I have been working around tektronix scopes for most of my life, and the early scopes all have ceramic terminal boards. I have never seen one broken. That includes 50 lb scopes that have been tossed into a scrap pile. I have been repairing and calibrating 2465 scopes for at least a decade, and I have never, ever, ever, seen a ceramic based hybrid that has been broken. Never. There are more than a half dozen such ceramic substrates in each scope. Ever seen a ceramic DIP package EPROM that spontaneously broke? A ceramic DIP packaged 68000 microprocessor? That is a heck of a big piece of ceramic! You really have to work to break these things. Google is your friend. Do some research on ceramics. -Chuck Harris cheater00 cheater00 wrote: > Interesting, good to know! I assume those materials were not available in > the 70s and 80s? Hybrids from those decades are known to be very fragile. > > On Mon, 10 Apr 2017 04:08 Chuck Harris, <cfharris@erols.com> wrote: > >> There are modern ceramics that are among the toughest things you >> will ever see in your life. >> >> A ceramic gun is entirely of ceramic. There are automotive >> engines made entirely of ceramic. As are some turbines used >> in turbochargers for engines. >> >> One of the things that can make ceramic extremely tough is >> to put it in a mold, and compress it to many tons per square >> inch, while in the green state. After that, it is already >> tough. Then fire it to sinter everything together. >> >> Google is your friend. >> >> Again, it isn't your mother's teapot. >> >> -Chuck Harris >> >> cheater00 cheater00 wrote: >>> Hi Chuck, >>> I can't talk about most of those applications but in the ones I know of >> the >>> ceramics are used for their hardness (ie ability to withstand >> deformation). >>> What we want is toughness which is a different thing (ability to >> withstand >>> breaking). Compromising hardness and toughness is why in a knife you only >>> harden the cutting edge, and you specifically watch out that the rest >>> doesn't harden, or you even reverse the hardening process on that part. >>> High hardness and low toughness is also why ceramic knives chip more >> easily >>> than metal ones. I haven't seen fully ceramic gun parts, interesting >> idea. >>> I know very little about gun parts. I wonder if it's just a layer over a >>> metal. Brake linings will have the benefit of a tough backing which will >>> enable load bearing. This is what you want from a pcb - toughness for >> load >>> bearing, and minimal hardness for reduced fragility. I don't suppose >> lathe >>> inserts will be made in the same way a pcb would be. If you know more >>> please let me know, I'd love to hear more about it. And yeah, I like to >>> break things when I can :) >>> >>> On Sun, 9 Apr 2017 18:37 Chuck Harris, <cfharris@erols.com> wrote: >>> >>>> Why exactly do you think ceramic is delicate? >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> and follow the instructions there. >> > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. >

-------- In message <58EB8A7E.8010708@erols.com>, Chuck Harris writes: >Google is your friend. Do some research on ceramics. We can add that the toughest materials, on pretty much all parameters, is what is becoming known as "metalic glass", which is just a fancy way of saying "ceramics made of metals". -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.