276 kilonewtons (kN) of thrust is generated by each of the four engines of a jumbo jet engine at take-off, which burns about 3 liters of kerosene per second in each turbine combustion chamber. Once the cruise speed of around 950 km/h has been reached, the Jumbo only needs 30 % of the maximum thrust of all engines, i.e. around 250 kN in total; this is around 90,000 hp (for comparison: an ICE puts around 12,000 hp on the rails, depending on the version). It is clear that the turbine blades (in the inlet, in the compressor or in the combustion chamber of an aircraft turbine) are exposed to the highest loads. Extreme speeds, extreme temperatures, high centrifugal forces and permanent bombardment by dust particles in the intake air. Therefore, only high-strength and heat-resistant materials (e.g. Inconel, Nimonic or Titanium) are used as materials. And these high-tech materials prove to be true killers of milling cutters during the milling process. This is why more and more users are turning to grinding for the manufacture and repair of expensive turbine blades.

We have developed a grinding process with which all geometries of a turbine blade can be machined in a single clamping operation for the Haas Multigrind® CB. This grinding process reduces tool costs, offers reliable processes and guarantees dimensionally accurate quality in the micrometer range. If you want to know more about this process, I look forward to your comments or questions.

Thomas Bader