CIBJO releases Gemmological Special Report: considers process of separating measurable facts from opinion; See Gemological Articles below.
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Mon Nov 18, 2019 4:47 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 7 posts ] 
Author Message
 Post subject: Is the temperature for Be diffusion higher than for Ti
PostPosted: Tue Sep 11, 2012 3:33 am 
Offline
Valued Contributor
User avatar

Joined: Thu May 18, 2006 5:08 am
Posts: 481
Location: Kuala Lumpur
Well I guess I asked in my title :) If anyone could just give me a quick answer to save me even more hours online I would appreciate it!

Thank you
Lucy

_________________
Intensive jewellery making classes in the heart of South East Asia
www.lucywalkerjewellery.com


Top
 Profile  
Reply with quote  
 Post subject: Re: Is the temperature for Be diffusion higher than for Ti
PostPosted: Tue Sep 11, 2012 11:15 am 
Offline
Moderator
User avatar

Joined: Thu Dec 13, 2007 3:42 pm
Posts: 4086
Location: the Netherlands
Titanium ions are bigger than Beryllium ions. You do the math...

There is a difference between the two diffusion treatments btw in terms of diffusion rates within economically viable circumstances. Keeping time and temperature equal, what would be the outcome regarding depth of penetration?


Top
 Profile  
Reply with quote  
 Post subject: Re: Is the temperature for Be diffusion higher than for Ti
PostPosted: Tue Sep 11, 2012 11:22 am 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19892
Location: San Francisco
The temperature can be offset by pressure, no?


Top
 Profile  
Reply with quote  
 Post subject: Re: Is the temperature for Be diffusion higher than for Ti
PostPosted: Tue Sep 11, 2012 11:29 am 
Offline
Site Admin
User avatar

Joined: Fri May 12, 2006 11:24 am
Posts: 7503
Location: Rome, Italy
even if the treatment is performed in "controlled atmosphere" i don't think that actually means pressures higher than 1 bar....... :wink:

ciao
albé

_________________
GemmoRaman-532 - GemmoFTIR - GemmoSphere - EXA


Top
 Profile  
Reply with quote  
 Post subject: Re: Is the temperature for Be diffusion higher than for Ti
PostPosted: Tue Sep 11, 2012 12:25 pm 
Offline
Gold Member
User avatar

Joined: Tue Jan 08, 2008 1:35 pm
Posts: 1175
Location: Vancouver, Canada
If I remember Dr. Emmett correctly, temperature and pressure are the same but time increases or penetration depth decreases with Ti compared to Be.

If I got that wrong, it's my lousy memory, not Dr. Emmett's excellent talk.

_________________
Lisa Elser, G.G.
http://www.lisaelser.com


Top
 Profile  
Reply with quote  
 Post subject: Re: Is the temperature for Be diffusion higher than for Ti
PostPosted: Tue Sep 11, 2012 12:44 pm 
Offline
Moderator
User avatar

Joined: Thu Dec 13, 2007 3:42 pm
Posts: 4086
Location: the Netherlands
Quote:
The temperature can be offset by pressure, no?


if you would increase pressure you would increase the melting temperature of corundum thus lowering the diffusion rate at the same temp-time level... You'd (theoretically) wanna lower the pressure in order to increase diffusion rates. Given the fact that we can only go one bar lower from where we are pressure is out of the equation somewhat... It's all about temp, time, ion size and structure of the stuff we want to pump those ions into as far as I'm aware...


Top
 Profile  
Reply with quote  
 Post subject: Re: Is the temperature for Be diffusion higher than for Ti
PostPosted: Wed Sep 26, 2012 11:56 pm 
Offline
Active Member
User avatar

Joined: Thu Nov 17, 2005 10:27 pm
Posts: 91
Location: Bangkok
Lisa Elser wrote:
If I remember Dr. Emmett correctly, temperature and pressure are the same but time increases or penetration depth decreases with Ti compared to Be.

If I got that wrong, it's my lousy memory, not Dr. Emmett's excellent talk.


You can read John's article based on his lecture here:

http://www.ruby-sapphire.com/pdf/Emmett-2011-Beryllium-and-Beefsteak.pdf

_________________
Richard W. Hughes
"The price of wisdom is beyond rubies"
ruby-sapphire.com
lotusgemology.com


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: Google [Bot] and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock