純アルミニウム/α相アルミナ界面の組織と強度

抄録

The interface strength and microstructure of α-alumina/pure aluminum were evaluated. In a solid-state joining, the strength of the joint increases with increasing joining temperature. In a liquid state joining, the strength gradually decreases due to the formation of an unjoined area. The strength,σ_b, is expressed by the following equation as a function of the unjoined area, A: σ_b=2.22A+143 (70%≤A≤100%). The highest strength reached 400 MPa when the interface is formed at around the melting temperature of aluminum. An aluminum layer becomes a single crystal when it is joined to a sapphire. The following crystallographic orientation relationship is established:
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Amorphous alumina islands are formed at the interface. In the amorphous alumina, spinel nano crystals grow from the sapphire and they have the same orientation relationship with sapphire as above.