chris_99 has quit [Remote host closed the connection]
Textmode has quit [Quit: "It was one dev, naked in a room with a carton of cigarettes, a thermos full of coffee and bourbon, and all his summoned angels."]
<_Sync_>
"handbook of semiconductor manufacturing technology"
<_Sync_>
which is a bit moot after all
<_Sync_>
but it makes a nice impression in the bookshelf
<_Sync_>
and I got it for 30 bux
<davidc__>
neato.
<_Sync_>
yup
<_Sync_>
there it is
<_Sync_>
'In addition, manganese dioxide slurries have been tried for metal CMP, with the manganese dioxide playing the role of both abrasive and oxidizer.'
<_Sync_>
it says silica, ceria and alumina for slurries
<_Sync_>
whitequark: the reason lab equipment is so expensive is because there usually is not a lot of it made and people know that their customers will pay the price
<_Sync_>
although sometimes it is also a thing of convenience
<_Sync_>
if I know I absolutely need some boron nitride in vacuum grade RIGHT NAO I can always just call up goodfellow and have it the next day
<davidc__>
yes, at prices approaching extortionate rates
<whitequark>
"know that their customers will pay the price" < this
<whitequark>
i.e. fuck anyone who is not sitting on a fat grant
<davidc__>
$171 for a 15cm x 15cm sheet of lexan.....
<whitequark>
$150 for a magnetic stirrer
<_Sync_>
that's pretty reasonable
<_Sync_>
I mean, I paid over 500 for my ika one
<whitequark>
do you live in US?
<_Sync_>
no
<davidc__>
I wonder if there's a website for open source / DIY lab equipment
<davidc__>
I should look this up
<_Sync_>
there probably is
<whitequark>
davidc__: yes
<whitequark>
teklalabs.org
<davidc__>
because I'm pretty sure I could make a mag stirrer for way less than $200
<whitequark>
it's kind of underwhelming
<_Sync_>
but dunno, there is not much sense in that for me
<_Sync_>
I want to get things done
<whitequark>
wait, whoa, 150 designs?
<_Sync_>
and not build stuff to get things done
<davidc__>
_Sync_: I mean, I understand that viewpoint too, but $500 for a heat plate could be $500 to get metal bits machined for my SEM
<whitequark>
^
<_Sync_>
sure
<whitequark>
it's reasonable if you get paid by someone in San Francisco
<_Sync_>
but I can just as easily get machining done afterwards
<davidc__>
or $500 worth of optics that I can;t make myself.
<whitequark>
I understand paying $500 for something that requires specialized equipment to create, or R&D cost
<whitequark>
a hot plate has been a hot plate for at *least* fifty years
<_Sync_>
yeah and they have been always expensive if you got a good one
<_Sync_>
unfortunately
<whitequark>
how the fuck do you make a bad hot plate
<_Sync_>
for me it is just a thing that has to work
<_Sync_>
make it out of steel and undersize the heater
<_Sync_>
for me, lab equipment has to work
<_Sync_>
it is not worth the time building it
<_Sync_>
on some things it is, but mostly it is not
<davidc__>
_Sync_: I find a lot of my lab equipment / tools work better because I built em myself :S
<davidc__>
I mean, there are quality MFGs out there, but they charge what they're worth
<davidc__>
which means that they're even further out of budget.
<_Sync_>
yeah I can see the point
<davidc__>
ALso, and a hot plate is sorta a dumb example of this; I like my own gear because its programmable. I just stick an ethernet interface on everything, and then I can script it from then on
<davidc__>
(again, ethernet-enabled-hotplate is sorta a dumb idea, but still)
<_Sync_>
sure
<_Sync_>
but if I'd build everything from scratch
<_Sync_>
I could not do the things I want to do
<davidc__>
Yeah, and I mean, I buy plenty of stuff... just usually end up reversing/modding it
<_Sync_>
shopping for machinery is even worse
<_Sync_>
I have a surface grinder, so I could just make good vises myself
<_Sync_>
but it is just easier to pay kurt to do it for me
<_Sync_>
but yeah it is amazing what even common labware costs
<_Sync_>
if you buy "retail"
<whitequark>
most glassware in RU costs cents to single dollars
* whitequark
is looking for some now
<whitequark>
but even trivial equipment is in hundreds of $
<_Sync_>
1000ml boro lab beaker is ~$7 here in single units
<whitequark>
$6.4
<whitequark>
hrm
<whitequark>
I guess glassware is fairly cheap everywhere
<davidc__>
_Sync_: are you in north america? if so, what supplier?
<davidc__>
here in .ca, all the vendor-sourced glassware is a ripoff
<davidc__>
I cat get cheapstuff from ebay/amazon/etc, but who knows what its actually made of
<davidc__>
"Oh, we said borosilicate glass? We just meant glass. Like window glass!"
<davidc__>
"Sorry about those cuts all over your hands and that nitric acid spill....."
<_Sync_>
well you in .ca don't even get proper gas so
<_Sync_>
no, I'm in germany
<davidc__>
_Sync_: proper gas?
<_Sync_>
91 octane
<_Sync_>
is max in cali iirc
<davidc__>
_Sync_: .ca is not cali :P
<davidc__>
I'LL HAVE YOU KNOW :P
<_Sync_>
err
<_Sync_>
my bad
<_Sync_>
long day
<_Sync_>
eh
<davidc__>
I know, just kidding, its all good
<_Sync_>
but yeah, I was wondering today about how cars get along in california thus the connection popped into my mind
<_Sync_>
because apparently the highest octane rating there is 91
<_Sync_>
easily to get
<davidc__>
maybe I'll need to get some of my .eu friends to buy and ship me some stuff... hmm
<_Sync_>
I don't think that is going to be much cheaper
jamie has quit [Excess Flood]
jamie has joined #homecmos
jamie has quit [Excess Flood]
jamie has joined #homecmos
chris_99 has quit [Quit: Ex-Chat]
Textmode has quit [Quit: "It was one dev, naked in a room with a carton of cigarettes, a thermos full of coffee and bourbon, and all his summoned angels."]
<SpeedEvil>
Borosilicate is easy.Just take regular glass and add boric oxide.
* SpeedEvil
needs some nice source of SiC elements.
<whitequark>
ebay.com/usr/advancer53
<whitequark>
sells off some astounding amounts of advanced NOS ceramics
<SpeedEvil>
SiC heating elements
<whitequark>
oh
<whitequark>
well idk take that ceramic and spin thin molybdenum wire around it as well
<whitequark>
do you need a source for molybdenum as well
<SpeedEvil>
No, the heating element is actually SiC
<SpeedEvil>
no wire
<whitequark>
oh
<whitequark>
cool
<whitequark>
I think I want that
<whitequark>
how does it work
<SpeedEvil>
It goes to ~1400C IIRC in air.
<whitequark>
fuck air, I have vacuum
<whitequark>
right now I plan to heat a carbide crucible and then use the radiated IR to heat my workpiece
<SpeedEvil>
I want a vacuum furnace that can do HIP
<whitequark>
er
<whitequark>
carbon
<whitequark>
carbon will be heated inductively
<whitequark>
using a watercooled copper coil
<whitequark>
I even figured out how to cast thin rods, though untested yet
<whitequark>
1700 is over working temperature for silica
<whitequark>
... well, it just melta at 1600
<whitequark>
And you don't want to use it over 1300 or something
<SpeedEvil>
I'd love to get to 1700C. But practically yes, that gets expensive
<whitequark>
1300 is up to what most commercial furnaces go. most even 1250. nichrome wire
<whitequark>
I think it is not very expensive when doing using the technique I want to.
<whitequark>
Which is, heat a graphite crucible as something that's refractory and conductive enough. Use IR to transfer heat. Use 6x molybdenum reflective shields around it to protect chamber.
<SpeedEvil>
There are all sorts of fun things.
<SpeedEvil>
AlN synthesis for example
<whitequark>
Use formed molybdenum sheet (maybe carbon, but that's too fragile) to hang the workpiece under the coil
<whitequark>
Mo is not expensive in that quantity
<whitequark>
The rest is pretty much trivial to construct.
<SpeedEvil>
What are you trying to heat?
<whitequark>
I have currently two use cases for this furnace
<whitequark>
One is sintering pure alumina, to make custom feedthroughs
<SpeedEvil>
Seems machining'd be easier
<whitequark>
(also because I think alumina is cool and I want to play with it)
<whitequark>
mm.
<SpeedEvil>
But :)
<whitequark>
its hardness is 9
<whitequark>
on mohs
<whitequark>
it's super hard on tools.
<SpeedEvil>
I thought diamond was OK
<whitequark>
I'm not sure if even SiC cuts it
<whitequark>
diamond is ok.
<SpeedEvil>
I haven't looked at it
<whitequark>
slow though.
<whitequark>
also very brittle.
<whitequark>
there's stuff like Macor if you want good machining
<whitequark>
alumina is mainly machined abrasively, you're sort of limited in the shapes you can make.
<whitequark>
and it is not a job you can just hand off to whoever.
<SpeedEvil>
I guess
<SpeedEvil>
HIP is cool. Take two grades of SS powder, '3d print' into a layered form. Now heat under vacuum and squeeze the voids out.
<SpeedEvil>
Does really nice things for the metallurgy.
<SpeedEvil>
(well, the HIP, the ther is just for prettyness)
<whitequark>
ew.
<whitequark>
more about alumina. I am not planning to press it into shape.
<whitequark>
I will be doing direct coagulation casting. Mix it with low mw polyacrylic acid, mill, then add MgO
<whitequark>
You have half an hour before it turns into a gel.
<whitequark>
A sol-gel process.
<SpeedEvil>
Interesting, then you just heat?
<whitequark>
yeah, you can just... take it out of the cast.
<whitequark>
before I make my vacuum sintering machine (vacuum really helps for heat isolation here. otherwise argon'd do)
<whitequark>
I will do some samples sintered in a commercially rented oven at 1300.
<SpeedEvil>
'with density >98%' that's damn god
<SpeedEvil>
oo
<whitequark>
normal alumina doesn't sinter at all at 1300
<whitequark>
I'm going to blow your mind the 2nd time, then :P
<SpeedEvil>
yeah - 'from solution' techniques with ~0 'particle' size can do so much better than making it from sand
<whitequark>
if you add 2% of both MnO and TiO2 to alumina, then you can fire it at 1300 at nearly theoretical density as well.
<whitequark>
Practically as good as at 1700.
<whitequark>
Also, using 4% of either doesn't work nearly as good, which is super neat.
<whitequark>
The issue with DCC is that dispersant acts as per surface area, and you need >10m²/g, in effect requiring particles of 0.3 micron or smaller
<whitequark>
So, fumed alumina.
<whitequark>
Linde A works, but it's sort of expensive as fuck.
<whitequark>
Also surprisingly hard to obtain.
<whitequark>
The 'normal' chinese alumina is 3 micron, fused alumina. Also lower limit when ball milling, too.
<SpeedEvil>
I wonder what flash powder makes
<SpeedEvil>
:)
<whitequark>
You can't DCC that, but you can slip cast that. Slip casting means you can't take it out though, so vacuum sintering is probably out anyway
<whitequark>
So I want to slip cast the 'doped' alumina, and then switch to DCC once I have the oven.