Atomic diffusion induced degradation in bimetallic layer coated cemented tungsten carbide

作者:Peng Zirong; Rohwerder Michael*; Choi Pyuck Pa; Gault Baptiste*; Meiners Thorsten; Friedrichs Marcel; Kreilkamp Holger; Klocke Fritz; Raabe Dierk
来源:Corrosion Science, 2017, 120: 1-13.
DOI:10.1016/j.corsci.2017.01.007

摘要

We investigated the temporal degradation of glass moulding dies, made of cemented tungsten carbide coated with PtIr on an adhesive Cr or Ni interlayer, by electron microscopy and atom probe tomography. During the exposure treatments at 630 degrees C under an oxygen partial pressure of 1.12 x 10(-23) bar, Cr (Ni) was found to diffuse outwards via grain boundaries in the PtIr, altering the surface morphology. Upon dissolution of the interlayer, the WC substrate also started degrading. Extensive interdiffusion processes involving PtIr, Cr (Ni) and WC took place, leading to the formation of intermetallic phases and voids, deteriorating the adhesion of the coating.

  • 出版日期2017-5-15