Understanding the role of microstructure for high-temperature reactions in tooling materials

Cutting tools are facing new challenges with increasing circularity: recycled tool materials contain detrimental contaminants, and recycling of workpiece materials increase wear during machining.

Many of these challenges are connected to chemical reactions (1) within the coating, (2) between coating and surrounding atmosphere and (3) between contaminants and cemented carbide in the base tool.I will use environmental transmission electron microscopy (ETEM) to study the evolving structure and composition, at the atomic scale, in industrial-style recycled tooling materials as they are exposed to high temperatures and reactive gases.

This should be contrasted with current state-the-art bulk measurements of powdered samples, which lack spatial resolution and the microstructural complexity of real tools.

Using ETEM, I will identify initiation sites within the tool materials and gain mechanistic understanding of (1) thermal and (2) oxidative reactions in the coatings, and (3) the role of contaminants in recycled cemented carbide.

The ultimate aim is to aid design of microstructures that enable increased circularity.The project is designed for a PhD student focusing on ETEM.

There is a natural progression of experimental complexity with in situ (1: year 1) heating and (2: year 2-3) oxidation of coating materials, and (3: year 3-4) the more complex interaction with contaminants in the cemented carbide. Molecular dynamics modelling will aid interpretation of the ETEM observations.