×
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

aluminium sand casting porosity

aluminium sand casting porosity

aluminium sand casting porosity

(OP)
Hi,
we have surface porosity problems with our aluminium castings.We use furane sand forour molds.The pores arise on heavy walls and on areas where cores are cast in.
In my opinion its a metal-sand reaction.
We found that if we modify with strontium the problem is way bigger than with sodium modification.
Is our sulphur level of 0,7% in our reclaimed sand a problem,or maybe our loss of ignition of 6%?
Thanks for any advise.

RE: aluminium sand casting porosity

My first thought is , How are you venting the core gas?

also have you contacted the AFS yet, or go to www.afsinc.org
for a start

RE: aluminium sand casting porosity

Have a look at your weather condition and amout of catalyst you are using.

I have experienced that on very cold days and if using heavy amounts of catalyst you get seurface porosity, is the inside of the sand mould when you break it open covered in small white spots or on the surface of casting?

Try using more reclaimed sand with lower resin content.

RE: aluminium sand casting porosity

(OP)
Hi sbi!
The core venting is not a problem as we get problemswith nad without cores.Strontium makes a big difference.

Hi etch!
U r right about the weather and the catalyst,it makes a difference.But we had the same additions last year and didnt have such problems.We run at 80-90% reclaimed sand and use HA and Eurotek(lately) furane binders.Any comment on the suppliers?

RE: aluminium sand casting porosity

do you coat your cores? try isomol 460.by the sounds of it you are casting lm6 or lm25?
i would guess your getting the sinks on LM6?
we use Eurotek and have very little problems.

one last thing check your blades on the mixer unit are clean and sharp. We have to do ours daily.

i have found that unsing sodium in some jobs leaves what i would call thumbprint indents in the metal casting, its not shrinkage just a localised depression.

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