50% Faster Turbine Blade Inspection

Checking critical dimensions of complex, high-volume parts can be difficult and time consuming, particularly when it’s necessary to conduct checks on 100 percent of parts manufactured.

Turbine and aero-engine blades are made using super-alloys capable of withstanding very high temperatures and pressures. Their shapes are typically complex, to maximize efficiency and reduce stress and fatigue. And yet, they are made using one of the oldest manufacturing techniques known to mankind: casting.

At Europea Microfusioni Aerospaziali (EMA) – a turbine blade manufacturing company based in Morra De Sanctis near Avellino, Italy, has perfected a wide range of micro-casting technologies, including those used for producing blades comprising of single crystals of metal alloy. The company also specializes in the lost wax micro-casting process, which begins with the creation of wax models obtained from metal molds.

These wax models are then coated with a ceramic material designed to withstand high temperatures. The wax is removed and the ceramic shell forms the mold for the super-alloy. Once solidified and cooled, the cast parts undergo heat treatment and finishing and all components are checked for dimensional accuracy, as well as structural integrity, using ultrasound, X-ray, and liquid penetrant testing.

Designing an efficient process for checking dimensional accuracy of turbine and aero-engine blades is challenging due to the complex geometry of the part and the requirement to check every blade.

The company had to find a solution that would allow it to improve the efficiency of the dimensional verification process in terms of quantity of parts measured in a unit of time. These checks are now performed using Renishaw’s PH20 5-axis probe head. Compared to using a 3-axis system, cycle times have been reduced by up to 50 percent.

EMA also invested in a Renishaw Equator™ flexible gauge, which allows the company to check the geometry and shape of high-volume parts quickly and efficiently.

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