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Zhou Lanying
School of Mechanical and
Vehicle Engineering,
Beijing Institute of Technology,
Beijing 100081, China
Zhou Huanjiang
Langfang Sandvik Ltd.,
Langfang 065001, China
Yang Jian
School of Mechanical
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Vehicle Engineering,
Beijing Institute of Technology,
Beijing 100081, China |
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ADHESION STRENGTH OF COATING
SUBSTRATE AND SURFACE
MORPHOLOGY OF PRETREATMENT*
Abstract: Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of in-creasing the adhesion strength of thin film coatings on cutting tool inserts by pretreating the inserts with sandblasting technique to obtain a desirable surface morphology of the inserts are presented. A geometric model representing the ideal surface morphology is established to enhance the nucleation density and adhesion strength of coating-substrate. Thin film coating experiment is con-ducted on the substrates of four different sample groups. Indentation and wear tests are performed on coated inserts to evaluate the effect of sandblasting on the adhesion strength of the coatings. A theoretical analysis is provided on the formation and growth of atom clusters in terms of the contact angle and the thermodynamic barrier of a substrate to predict thin film nucleation.
Key words:
Thin film coating Adhesion strength Surface
morphology |