×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

What is a "divacancy"

What is a "divacancy"

What is a "divacancy"

(OP)
I recently came across an explanation that attributed a behavior (corrosion fatigue, if you must know) to the formation of "divacancies".  Wiktionary defines a divacancy as:

A pair of vacancy defects in a crystal.

I am a member of ASM and a search through the journals available on their website (Like Met Trans A) did not reveal anything.  I would not have expected it to.

Can someone please shed some insight on what a divacancy is?  

Maybe a link to a website with an illustration, or a more intuitive explanation.  

How is a divacancy different from a vacancy?

What is special about divacancies?

RE: What is a "divacancy"

(OP)
The link to the website with the mathematical derivation of the likelihood of existence of divalancies was certainly interesting.

May I supplement my posting to include a request for a short summary by a member, or an illustration of what a divalency "looks like" or why they are important to metallurgists?

 

RE: What is a "divacancy"

Divacancies are discussed in terms of the anodic dissolution mechanism, which is used to explain stress corrosion cracking and corrosion fatigue.  The following abstract is from a Met Trans article on the subject:

A unified mechanism of stress corrosion and corrosion fatigue cracking
http://www.springerlink.com/content/p122741634g44033/

Here is a Google Scholar link for keywords corrosion fatigue + divacancy:

http://scholar.google.com/scholar?hl=en&as_sdt=0,14&q=%22corrosion+fatigue%22+divacancy
 

RE: What is a "divacancy"

(OP)
Thank you for your reply TVP;

Funny that you would link me to that particular article.  That is the very article that caused me to wonder what a divancancy is.

I understand what the article says about the action of divacancies, but what is a divacancy?

Is there any other mechanism that depends on divacancies?

What does one look like (obviously schematically)?

I guess I am a visual thinker.

RE: What is a "divacancy"

There will be schematic representations in books devoted to crystallography, lattice defects, etc.  Here are some examples:

Intrinsic Point Defects, Impurities, And Their Diffusion In Silicon
http://books.google.com.br/books?id=1Bhoe2xQsEEC&pg=PA121&dq=divacancy+lattice&hl=en&sa=X&;ei=w-SFT-y-JI2w8ASN8IixCA&;redir_esc=y#v=onepage&q=divacancy%20lattice&f=false

A First-principles Methodology for Diffusion Coefficients in Metals and Dilute Alloys
http://books.google.com.br/books?id=mjeSuQpk1mAC&pg=PA42&dq=divacancy&hl=en&sa=X&;ei=yuWFT8W0Lse68AGH2f2vCA&;redir_esc=y#v=onepage&q=divacancy&f=false
 

RE: What is a "divacancy"

(OP)
TVP,

That was a terrific response.  I wish I could give you more than one star.  A link to a sketch, and another link to a concise description.

Exactly what I wanted.

Thanks again.

Bob

RE: What is a "divacancy"

I aim to please. smile

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources