Improving metal cutting tools using X-rays

Metal machining, whereby metal components are made into different shapes and dimensions, requires high-performance cutting tools with excellent wear properties that can cut metals fast, thus increasing the production rate.  

More information about tool wear behavior is needed to develop the next generation cutting tools. Important knowledge can be gained by characterizing chemical changes across the surface of the cutting tools. 

X-ray absorption spectroscopy techniques (XANES and EXAFS) are ideal for studying tool wear behavior. The high spatial resolution of the method can provide information about small, local changes in the atomic structures of the coatings on the cutting tools, thus revealing important information about how coating selection impacts the tool performance. 

Coatings studied in atomic detail 

The research team from Seco and Linköping University conducted their experiment at the Balder beamline at MAX IV in Lund. Five samples of worn cutting tools were prepared.  

The samples were coated in a chemical compound of the three elements titanium, aluminum, and nitrogen (TiAlN) that offers high resistance to heat and oxidation. The TiAlN coating enables higher cutting speeds which accelerates the working processes. In this study, each sample contained a different aluminum content. 

The results show that changes in the atomic content of the surface could be detected depending on the aluminum concentration.  

Furthermore, a change in temperature across the tool surface and a variation in the coating response to the elevated temperature depending on aluminum content was revealed. 

The data from the experiment illustrated the improved sensitivity of X-ray absorption spectroscopy to the local structure of the coating compared to, e.g., X-ray diffraction.  

Results will guide the development of more efficient tools 

The collaboration illustrates that X-ray absorption spectroscopy can be used to study the chemical interactions of worn tools. The technique can add important knowledge on the wear behavior of the coatings. 

This knowledge can be used to develop future experiments to explore the behavior of materials during machining further and support the development of more optimized and efficient tools. 

“As researchers, we always want to study and understand our materials at the highest possible detail. These techniques help us explore the unknown.”

Jon Andersson, Seco Tools