Abrasive water-jet model could enable lower-cost milling

New research could enable lower-cost milling on difficult materials using adapted water-jet cutting machines.

Engineers in Spain have developed a model for predicting and controlling the depth of cuts made by abrasive water jet (AWJ) machinery, which was previously unpredictable.

AWJ equipment blasts materials with high-pressure water and abrasive particles in order to erode and cut them without causing any heat damage, as traditional milling can do to some materials such as titanium.

But fluctuations in the water’s speed and pressure and the geometry of the particles mean that milling by AWJ creates surfaces with variable depths.

The engineers from research company Tecnalia and the University of the Basque Country used information on process parameters such as water pressure, as well as machine acceleration, tool path and materials, to predict the depth at every point of a machined surface.

‘This model is also used to find the optimum process parameters and milling strategy to reach a desired depth in any material,’ Tecnalia researcher Amaia Alberdi told The Engineer.

The researchers hope to use the model to redesign AWJ cutting machines to make them suitable for milling, which they say could produce a manufacturing breakthrough in industries, including aerospace, marine, rail and automotive.

Using traditional milling techniques on certain materials can produce a high level of tool wear, meaning expensive tools are needed. AWJ milling would avoid this problem while preventing heat damage to the material’s structural properties.

‘The AWJ milling is especially advantageous for low-machinability materials,’ said Alberdi. ‘For other materials, [such as] aluminium, the conventional machining is fully understood and optimised, so the AWJ technology can’t compete with it.’