Walter AG, parent company of Walter USA, together with machine tool manufacturer Starrag AG, has won the MM Award for Innovation for having the most innovative exhibit at EMO 2013 in the milling category with its production-scale machining of turbine blades with CO2 based cryogenic cooling.
Walter AG and the Swiss manufacturer of machining centers Starrag first conducted a live demonstration of the jointly developed solution for cryogenic milling with CO2 cooling in spring 2013. The most prominent feature of the approach is the liquid supply of CO2 coolant through the machine, spindle, toolholder and tool, right to the cutting edge—all without loss of pressure at room temperature. Cooling to a maximum of minus 99° F first occurs at the nozzle, when the CO2, which has been in liquid form until that point, expands. Users are able to machine up to 70% faster in comparison to dry machining. Conversely, the cryogenic CO2 cooling doubles the tool life, as long as the cutting parameters are not increased.
The developers at Walter and Starrag have refined their solution even further by developing a second media channel that supplements the CO2 cooling. This channel can be used for aerosol or minimum quantity lubrication (MQL) for milling high-strength alloys for extremely heat-resistant turbine blades. Because both media, CO2 and MQL, are completely separated and only come into contact with one another at the tool cutting edge, this allows for highly efficient lubricating.
“We are delighted with the award but we are not going to stop there,” said Mirko Merlo, CEO of Walter AG, “because Walter and Starrag are already testing a three-channel solution, in which CO2, aerosol and even emulsion can be guided through the spindle.”
In the future, Walter will provide tools with cryogenic process cooling under the brand name Cryo·tecTM. Machines from Starrag are already available with optional CO2 cooling. The MM Award, from MM MaschenenMarkt is open exclusively to exhibitors at EMO and must feature a commercially available machine, system, process or tool.
For more information, visit www.walter-tools.com.