Intefix – Intelligent Fixtures for the machining of low rigidity components
Turning of Low-pressure Turbine casing
The objective is the improvement of the turning performance of a turbine case made of low machinability Inconel 718 alloy. The performance of the machining process is limited by the presence of vibrations and deformations that lead to limited cutting conditions and reduce the tool lifespan, affecting also the quality of the workpiece. The work performed has allowed the identification of the main limitations of the current fixture and the manufacturing process. The improvement of the workpiece behavior has been tackled using three approaches:
- Active modification of mechanical impedance.
- Controlled deformation.
- Use of CFRP for locators. – This solution deals with the introduction of passive CFRP elements to substitute the metallic rings used as locators in the current fixture. The use of CFRP increases the damping (10 times higher than steel) of the fixture without reducing the stiffness. In this way, the effect of the shocks can be minimised.
The developed intelligent fixture allows the improvement of the workpiece behavior and the cutting conditions can also be increased obtained a better machining process performance.