알루미나/브레이징합금 계면에 형성된 반응생성물의 미소조직과 접합대상금속의 역할 = Role of Adhered Metal and Microstructure of Reaction Product formed at the Alumina/Braze Alloy Interface

다국어 초록 (Multilingual Abstract)

The Al₂O₃/STS304, Al₂O₃/Cu and Al₂O₃/Al₂O₃joints were vacuum-brazed with three types of Cu-Ag-Ti brazing alloy at 1193 K for 1.2 ks. The microstructure and microchemistry of reaction products formed at the Al₂O₃/braze alloy interface have been investigated by glancing x-ray diffractometer (G-XRD) and scanning electron microscope(SEM) equipped with energy-dispersive spectrometer (EDS). The reaction products of Al₂O₃/STS304 joint were a layered structure consisted of TiO (Monoclinic, ao=5.85Å, bo=9.34Å, co=4.14Å, Cu₂Ti₄O (Cubic, ao=11.49Å and Fe₂Ti₄O (Cubic, ao=11.297Å). For the Al₂O₃/Cu and Al₂O₃/Al₂O₃joints, reaction products were a layered structure consisted of TiO and Cu₂Ti₄O. For the Al₂O₃/STS304, Al₂O₃/Cu joints, the thickness of reaction product layer was in creased with Sn-addition and rapidly decreased with Al addition in Cu-Ag-Ti alloy. Type of reaction products was not varied with additional elements. The formation of TiO compound resulted from redox reaction between Al₂O₃and segregated Ti, but the Cu₂Ti₄O and Fe₂Ti₄O compounds was formed by solid-state reaction between TiO and Cu/Fe of brazing alloy and adhered metal respectively. The Cu₂Ti₄O and Fe₂Ti₄O compounds can be considered as (Cu, Fe)₂Ti₄O, because both of compounds have the nearly same crystal structure and lattice constant. That is, that compound seems to be formed as a result of the rearrangement of structure from monoclinic to cubic after the Cu and Fe atoms is diffused into the ordered vacant sites of pre-fomed titanium monoxide(TiO_(1±X), x=0.1). The formation of that compound means that the Cu and Fe atoms into TiO have the faster diffusion velocity than the other elements such as Ag, Al, Sn, Ni and Cr. Conclusively the thickness of reaction product layer depends on the diffusion velocity of metallic elements into the TiO layer and the additional elements in Cu-Ag-Ti brazing alloy effectuate the variation of that diffusion velocity.

목차 (Table of Contents)

• 1. 서론
• 2. 실험방법
• 시편제작
• 제어압연
• 집합조직 측정(결정방위분포함수)
• 미세조직 관찰
• 3. 실험결과 및 고찰
• 미세조직
• 오스테나이트 변형집합조직
• 변태집합조직
• 4. 결론