DEVELOPMENT OF DENTAL GOLD ALLOYS WITH AGE-HARDENABILITY AT INTRAORAL TEMPERATURE

研制了具有口内时效硬化性的牙用金合金。在等原子AuCu合金中分别加入3或6 %的Ga、Al、Zn、In、Ni或Pd，考察了添加剂对合金低温时效淬透性的影响。含Ga、Al或Zn的合金表现出优异的低温时效硬化性。含6 （% Ga）或6 （% Al）的合金在37℃下时效后，硬度在1 ~ 10天内翻倍。另一方面，Ni或Pd的加入降低了合金的低温时效淬透性。在铸态合金中没有明显的硬化，但固溶处理仅几分钟就提供了足够的时效硬化性。低温时效硬化速率与合金的熔化温度密切相关。结果表明，添加Ga、Al或Zn的AuCu合金具有足够的时效硬化性，可用于口腔环境的临床应用。

Dental gold alloys with age-hardenability at intraoral temperature were developed. Either 3 or 6 at% Ga,Al,Zn,In,Ni or Pd were added to the equiatomic AuCu alloy and the effect of additives on the low temperature age-hardenability was examined. Alloys containing Ga,Al or Zn exhibited excellent low temperature age-hardenability. The hardness of an alloy containing 6 at% Ga or 6 at% Al was doubled in one to ten days by aging at 37ﾟC. On the other hand,addition of Ni or Pd decreased the low temperature age-hardenability. Pronounced hardening was not demonstrated in an as-cast alloy,but solution treatment for only a few minutes provided enough age-hardenability. Age-hardening rate at low temperature related closely with the melting temperature of the alloy.It is concluded that Ga,Al or Zn added AuCu alloy is expected to have enough age-hardenability for clinical use in the oral environment.