发明名称 |
Conversion of doped polycrystalline material to single crystal material. |
摘要 |
A solid state method of converting a polycrystalline ceramic body to a single crystal body includes the steps of doping the polycrystalline ceramic material with a conversion-enhancing dopant and then heating the polycrystalline body at a selected temperature for a selected time sufficient to convert the polycrystalline body to a single crystal. The selected temperature is less than the melting temperature of the polycrystalline material and greater than about one-half the melting temperature of the material. In the conversion of polycrystalline alumina to single crystal alumina (sapphire), examples of conversion-enhancing dopants include cations having a +3 valence, such as chromium, gallium, and titanium. The polycrystalline body further can be inhomogeneously doped to form a first portion of the polycrystalline body that is doped to the selected level of the conversion-enhancing dopant and a second portion that is not doped such that heating the doped polycrystalline body causes conversion of first portion to a single crystal structure and the second portion retains a polycrystalline structure. <IMAGE> |
申请公布号 |
EP0667404(A1) |
申请公布日期 |
1995.08.16 |
申请号 |
EP19950300260 |
申请日期 |
1995.01.17 |
申请人 |
GENERAL ELECTRIC COMPANY |
发明人 |
SCOTT, CURTIS EDWARD;KALISZEWSKI, MARY SUE;LEVINSON, LIONEL MONTY |
分类号 |
C30B1/02;C30B1/00;C30B29/20 |
主分类号 |
C30B1/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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