Linköping Extends Lifetime, Performance of Metal Cutting Tools

Linköping University (LiU) researchers have developed a new solution for increasing the performance and lifetime of metal cutting tools.

The university’s theoretical model enables simulations for showing what happens in hard cutting materials as they degrade.

Titanium-aluminium nitride is a ceramic material commonly used as coating for metal cutting tools.

When aided by a titanium-aluminium nitride thin film, the cutting edge of a coated tool becomes harder, helping increase the lifetime of the tool.

A significant feature of the coated surface is that it becomes even harder during the cutting process – a phenomenon researchers generally allude to as ‘age hardening.’

The alloy is nevertheless sensitive to high temperature, reports Linköping associate professor Kostas Sarakinos.

A few minutes of cutting operation in a truly hard material subjects the cutting edge of the tool to such a high pressure that it is heated to nearly 900 degrees or above.

At temperatures up to 700 degrees, the material is unharmed, but it starts to degrade at higher temperatures.

Until now, no one has been able to determine what happens at the atomic level inside the thin film during the cutting process.

The Linköping team – featuring Georgios Almyras, Davide Sangiovanni, and Sarakinos – is the first to develop a reliable theoretical model to show what exactly happens in the material, with picosecond time resolution.

They have used the newly developed model and LiU’s supercomputer to simulate events in the material, showing which atoms are displaced and the consequences this has for the properties.

According to the researchers, the model calculates the forces between the atoms in the material. These calculations are then implemented by utilizing a mix of machine learning algorithms and AI.

“The agreement is very good,” reports Sarakinos. “It’s important that we have calculated also properties that we know, because then we can be sure that the calculations and predictions of the model are reliable.”

The new method could help manufacturing companies like Sandvik, ABB and Seco Tools, manage their expenditure on developing tools with greater hardness and resistance to wear.