Adhesion strength of cordierite glass-ceramic coatings on molybdenum substrates

摘要

Cordierite glass-ceramic coatings do not bond to molybdenum directly because of the absence of a suitable transition layer. Dual metallic interlayers of copper/chromium and nickel/chromium were electroplated on the substrates to enhance adhesion. The adhesion of the glass-ceramic coatings was evaluated by indentation testing and a modified analytical method based on interfacial fracture toughness. Quantitative chemical analyses of the interfaces were used to explain differences in fracture toughness among samples with different interlayers. Of those tested, the best interface for adhering glass-ceramic coatings to molybdenum was found to be a 4 #mu#m chromium over 2 #mu#m copper on molybdenum.