AW: DTM Zircon Sand Postcuring

From: Shellabear, Michael (Shellabear@EOS-GmbH.de)
Date: Wed Aug 13 1997 - 17:09:23 EEST


Dear Trevor,

We have extensive experience of producing large sand moulds successfully
and accurately with EOSINT S. Our application engineers will contact you
directly to give you some tips. Any other of our customers who have any
questions are of course also invited to contact our application
department directly.

Best Regards,

Mike Shellabear

********************************************
Dr. Michael Shellabear
Assistant to the Management Board
EOS GmbH Electro Optical Systems
Pasinger Strasse 2
D-82152 Planegg/Munich, Germany

Tel.: +49 (0) 89 85685-122
Fax: +49 (0) 89 8598402
Email: shellabear@eos-gmbh.de
********************************************

        ----------
        Von: IAN HALLIDAY[SMTP:ESRMJ@atcmail.wmg.warwick.ac.uk]
        Gesendet: Donnerstag, 7. August 1997 18:09
        An: rp-ml@bart.lpt.fi
        Betreff: DTM Zircon Sand Postcuring

        Hello All Sand Users,

        We are having some problems with the postcuring of the DTM
Zircon
        sand when producing large sand boxes. The two sand boxes are 310
x
        280 x 140 mm in size. The built perfectly on our 2500
Sinterstation
        but both attempts to postcure them ended in failure. The first
        attempt involved ramping up to 200 C in 1 hr and holding at
temp. for
        2 hrs. The sand box had warped and cracked under its own weight
and
        was a chocolate brown colour. The second attempt involved 1 hr
at 65
        C, 1 hr at 110 C and 1 hr at 150 C. The sand was okay upto 110 C
but
        after 0.5 hr at 150 C had warped and cracked very badly,
although it
        was the required olive green colour.

        Has anyone had experience in postcuring zircon sand in large
blocks.
        We can do it for small pieces but not large blocks. Do you need
to
        support the block in glass beads? Is the any benefit in surface
        curing using a flame or hot air gun?

        We have also experienced the same problem postcuring the same
sand
        moulds produced on our EOSINT S in silica sand!

        Hope to hear any of your experiences

        Dr Trevor Illston
        Rover Group RP&T
        University of Warwick
        United Kingdom
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        Rover RP&T,
        3rd Floor ATC,
        University of Warwick,
        Coventry,
        CV4 7AL,
        UK

        Tel - 0044 1203 524907
        Fax - 0044 1203 524878

        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



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