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Effect of casting atmosphere on the quality of Ti‐crowns
Author(s) -
SUNNERKRANTZ PÄR ANDERS,
SYVERUD MORTEN,
HERÖ HÅKON
Publication year - 1990
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.1990.tb00972.x
Subject(s) - crucible (geodemography) , casting , torr , mold , materials science , metallurgy , brittleness , impurity , atmosphere (unit) , refining (metallurgy) , composite material , chemistry , physics , computational chemistry , organic chemistry , thermodynamics
– Ti has a strong affinity to elements like O, N, and C. During melting a non‐reacting crucible and vacuum and/or Ar‐gas protection therefore have to be used. If the impurity content becomes too high, the material turns hard and brittle. In the present work vacuum/Ar‐pressure casting of crowns has been carried out at different air pressure levels. Recording of hardness on cross‐sections of the castings and the degree of mold filling show that an air pressure level < 1 torr in the melting chamber and < 10 torr in the mold chamber is sufficient to obtain sound castings of a small size like a crown.