Deconvoluting residual stress effects on the toughness of (Hf-Nb-Ta-Zr)C multi-element carbide coatings (11/04/23)

Speaker & Affiliation:

Dr. Hariprasad Gopalan
Institute of Applied Materials, Karslruhe Institute of Technology, Karlsruhe

When ?

11th April, 2023 (Tuesday), 4.00 pm (IST)

Venue

KPA Auditorium, Department of Materials Engineering

Abstract:

Multi-element hard coatings inspired by high entropy alloys offer a way to explore the hardness-toughness tradeoff in materials science. In this talk, I will present sputter deposited (Hf-Nb-Ta-Zr)C as a promising material to obtain super hardness and respectable toughness. Extensive microstructural and mechanical characterization was performed to understand the specific roles of microstructure and residual stress on the fracture behaviour. A combination of nanoindentation and in situ microcantilever toughness testing quantitatively reveals the relationship between apparent and true toughness of hard coatings.