The oxidation resistance of the diffusion aluminide bond coat (BC) is compromised largely by interdiffusion (ID) effects on coated turbine blades of aeroengines. The present study is designed to understand the influence of ID on βNiAl coatings or BC. In this regard, nickel substrate and CMSX-4 superalloy are deposited. In total, four sets of BCs are developed, i.e. pure βNiAl (on Ni substrate), simple βNiAl (on CMSX-4 substrate), Zr-βNiAl (on CMSX-4 substrate) and Pt-βNiAl (on CMSX-4 substrate). The main aim of this study is to understand the interdiffusion of Al, Zr and Pt during preparation and oxidation. In addition, the beneficial effects of both Zr and platinum are assessed. Pure βNiAl and simple βNiAl show Ni-outdiffusion, whereas for platinum inward diffusion to the substrate is noticed under vacuum treatment. Interestingly, Zr-βNiAl shows the least ID in all BCs and exhibit stability under both vacuum and oxidation treatments. However, its spallation resistance is slightly lower than that of Pt-βNiAl BC. All BCs show similar oxide growth trends, except for Zr-βNiAl, which exhibits two-stage oxidations, i.e. transient and steady-state. Moreover, it is suggested that the localized spallation in all BCs is caused by βNiAl - γ’-Ni3Al transformation.

Si(100)기판상에 여러 가지 두께의 Au박막을 선행 증착(pre-deposition)한 후, 각각의 Au박막상에서의 Cu-MOCVD박막의 초기 핵생성과 성장 기구를 고찰하였고, 또한 각 계면에서의 상호 확산 거동을 여러가지의 분석 장비를 이용하여 조사하였다. 30Å두께의 Au 박막은 수소 가스 분위기중의 열처리에 의하여 평탄한 표면 상태에서 불연속의 응집된 도상(island)형태로 변화(Si 전체 표면중 약 20%)하였다. 반면에 1500Å두께의 Au박막상에서 성장한 Cu-MOCVD박막은 두께 증가에 따른 미세구조의 차이, 즉 Cu박막중으로 Au원자의 확산여부는 Au박막에 유기되는 열응력(thermal stress)을 완화하는 과정에서 일어난 결과이다.