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A New Tool for Evaluation of Intrinsic Mechanical Properties of Multilayered Coatings

2001; Maney Publishing; Volume: 17; Issue: 6 Linguagem: Inglês

10.1179/026708401322911374

1743-2944

Maria Nordin, Staffan Jacobson,

Metal Alloys Wear and Properties

A new tool is proposed for characterising intrinsic mechanical properties and wear mechanisms of multilayered coatings. In the present work multilayered coatings have been investigated with respect to their tendency to interlamella spalling in abrasion, i.e. the tendency for spalling within the coating at the lamella interfaces. This tendency is proposed to be caused by an excessive difference in the residual stress between the lamella materials and is triggered by the additional stresses imposed by abrasive diamond grits. Thick lamellae will have a stronger tendency for spalling than will thinner layers, as a result of a higher shear force in the lamella interfaces. The method is evaluated on a set of five multilayered PVD coatings, including both metallic/ceramic (Cr/CrN and Ti/TiB 2 ) and ceramic/ceramic systems (TiN/CrN, TiN/NbN, and TiN/TaN). Each coating is represented by a number of different lamella thicknesses, ranging from approximately 50 to 900 nm.