AVS 47th International Symposium
    Surface Engineering Monday Sessions
       Session SE+TF-MoM

Paper SE+TF-MoM7
Growth and Characterization of ZrN/ZrB@sub 2@ Nanolayered Coatings for High Temperature Applications

Monday, October 2, 2000, 10:20 am, Room 201

Session: Hard and Superhard Coatings
Presenter: K Martin, Applied Thin Films, Inc.
Authors: K Martin, Applied Thin Films, Inc.
J. Ji, Applied Thin Films, Inc.
I. Kim, Applied Thin Films, Inc.
S.A. Barnett, Applied Thin Films, Inc.
A. Madan, Northwestern University
P. Hedge, Kennametal, Inc.
A. Inspektor, Kennametal, Inc.
Correspondent: Click to Email
There is a great need for cutting tool coatings that perform well at elevated temperatures, both because of the desire to cut at higher rates and to eliminate coolant fluids. However, current cutting-tool coating materials fail rapidly under these conditions because of poor high-temperature properties. The ZrN/ZrB@sub 2@ nanolayered system is expected to provide a unique combination of properties including high hardness, excellent stability at elevated temperatures, low chemical solubility in Fe and good thermal expansion match with cemented carbide tools. In this investigation, ZrN/ZrB@sub 2@ nano-layered coatings were deposited using a dual-cathode magnetron sputtering system. The key properties including hardness, adhesion, and residual stress were evaluated as a function of composition, bilayer period, and substrate bias. The hardness values for as-deposited coatings ranged from 30-38 GPa and increased to 49 GPa after annealing at 1000°C. Low and high angle XRD revealed that the superlattice structure was stable at elevated temperatures. The increase in hardness after annealing is attributed to the transition of the soft amorphous ZrB@sub 2@ to the crystalline form. Adhesion testing verified that the coatings adhered well on cemented carbide inserts even after annealing at 1000°C.