DTM Zircon Sand Postcuring

From: IAN HALLIDAY (ESRMJ@atcmail.wmg.warwick.ac.uk)
Date: Thu Aug 07 1997 - 19:08:59 EEST

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,
CV4 7AL,

Tel - 0044 1203 524907
Fax - 0044 1203 524878


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