TTL
Fully automated repair of Nozzle Guide Vanes
For over 20 years TTL have been at the forefront of CNC machining technology. Their manufacturing expertise spans several important industry sectors including Gas Turbines, Automotive, Mould & Die and Pharmaceutical. Their Adaptive Machining software, a 5-axis milling centre, 3D laser scanning and an Erowa Robot enabled TTL to find a solution to a complex machining problem.
The Problem ...
The repair of Nozzle Guide Vanes (NGV’s) usually involves a number of processes. These include removal of thermal barrier coatings, inspection, brazing to fill cracks and surface erosion and ultimately, recoating. An unfortunate side-effect of the brazing process is that the gas-path surfaces no longer conform to the desired shape and the cooling holes often become filled with new braze material. Brazing also leaves the component in a very rough state with inconsistent wall thickness and aerofoil geometry, symptoms that have been relieved in the past by manual blending and polishing.
The Solution...
TTL have developed an adaptive repair process that addresses these problems. Using a CNC measuring machine (CMM) equipped with a high resolution stripe laser measuring device, the complete gas path surfaces are scanned, and the resulting data captured onto a computer.
The fully automatic scanning cycle - which takes around two minutes - generates a data set of approximately 150,000 points which is processed and analysed by the Adaptive Machining software, resulting in the generation of 5-axis machining paths which are unique to each individual component.
Ultimately, a completely new set of 5-axis machining paths are generated to remove all unwanted braze material from the entire gas path leaving a part which conforms to stringent surface finish, external geometry and wall thickness requirements.
To reduce the need for operator intervention, an Erowa Robot Compact pallet handling system has been integrated into the solution. Extensive use is made of the Erowa PowerChuck zero point tooling to facilitate accurate transfer of parts from the CMM to the machine tool and as parts are loaded into the cell, the component type and ID are identified uniquely. With the use of Erowa’s Manufacturing Control software the cell can operate with a theoretical batch size of 1, and the potential for 18 hours continuous lights out operation.
Source: TTL Ltd T: +44 (0) 1844 296650 W: www.ttl-solutions.com Contact: Paul Walton
Sept 2010
For over 20 years TTL have been at the forefront of CNC machining technology. Their manufacturing expertise spans several important industry sectors including Gas Turbines, Automotive, Mould & Die and Pharmaceutical. Their Adaptive Machining software, a 5-axis milling centre, 3D laser scanning and an Erowa Robot enabled TTL to find a solution to a complex machining problem.
The Problem ...
The repair of Nozzle Guide Vanes (NGV’s) usually involves a number of processes. These include removal of thermal barrier coatings, inspection, brazing to fill cracks and surface erosion and ultimately, recoating. An unfortunate side-effect of the brazing process is that the gas-path surfaces no longer conform to the desired shape and the cooling holes often become filled with new braze material. Brazing also leaves the component in a very rough state with inconsistent wall thickness and aerofoil geometry, symptoms that have been relieved in the past by manual blending and polishing.
TTL have developed an adaptive repair process that addresses these problems. Using a CNC measuring machine (CMM) equipped with a high resolution stripe laser measuring device, the complete gas path surfaces are scanned, and the resulting data captured onto a computer.
The fully automatic scanning cycle - which takes around two minutes - generates a data set of approximately 150,000 points which is processed and analysed by the Adaptive Machining software, resulting in the generation of 5-axis machining paths which are unique to each individual component.
Sept 2010
