1. 1 Laser Drilling of Cylindrical and Shaped Holes NCMS/CTMA Symposium: Track 1b Terry L. VanderWert PRIMA North America, Inc.

2. 2 Outline  Laser drilling technology overview  Capability  Applications  Recent developments – benefits of integration  Repair applications  Potential benefits  Potential projects  Summary

3. 3 Customers Serving Turbine Engine Manufacturers

4. 4 Incremental improvements have led to substantial increases in the number of cooling holes in new engine designs. Laser drilling is fast relative to competing methods for small holes – translates into substantially lower cost. No tooling means lower cost, faster turnaround – the ‘tool’ is a focused beam of light Flexible – single part lot sizes Easily interfaced with CAD/CAM Laser Drilling - An Enabling Technology Drills/machines a wide range of materials At shallow angles Complex shapes

5. 5 Laser Drilling of Cylindrical Cooling Holes Typical applications – Cooling holes in blades, vanes, combustors, and afterburners 0.3 to 1 mm diameter holes at 15-90° in cast, sheet, and machined components, uncoated and with TBC Rates – 0.25 to 5 holes per second Airfoil Air flow Film cooling holes

6. 6 Laser Drilling of Shaped Cooling Holes Film cooling holes increase efficiency of cooling air by 30%, reducing the amount of air required for cooling. Used sparingly today because of their cost when produced using EDM.

7. 7 Recent Developments by PRIMA North America for New Part Manufacturing and Repair Process control for improved airflow consistency Optimum laser process parameters for cylindrical shaped holes Drill at focus Breakthrough detection Optical focus control (for TBC) ‘Simple’ shaped hole drilling The bottom line? More consistent holes

8. 8 Repair Applications for Laser Drilling Re-drilling of cooling holes. Some cooling holes become blocked during repairs by welding or brazing Holes must be re-drilled to restore component airflow. Blades and vanes repaired by welding or brazing. Cooling holes become blocked and component suffers some distortion Cooling holes re- drilled by laser

9. 9 Repair Applications for Laser Drilling Removal of TBC overspray Coatings must be removed before any repairs can take place. Re-coating partially fills cooling holes and this must be removed to restore component airflow. Coating must be stripped from components before repair. Repaired components must be re-coated. The new coating covers existing cooling holes Coating overspray removed by Laser Issue: Amount of new coating in the hole varies

10. 10 Potential benefits of laser drilling for repair depots  Reduced costs  Reduced turnaround time - keep aircraft flying  Provides a method for producing engines having increased engine performance  Thermal barrier coatings  Film cooling – shaped and cylindrical

11. 11 Potential Projects Laser source technology for combined machining and drilling in uncoated as well as thermal barrier coated (TBC) components Automation of set-up and drilling Probe repaired components to compensate for deviations in shape and position Identify actual hole locations In process gauging - improve process efficiency and quality by automating part inspection

12. 12 Laser source technology for combined machining and drilling Objective - Develop laser source capable of both pulsed drilling of cylindrical holes and ablative machining of shaped holes. Challenges – Produce laser source having both ms (deep hole drilling) and µs (machining) pulse widths, with high beam quality. Potential return – Improve productivity and reduce cost for laser drilling by taking advantage of the speed of laser machining and producing complete shaped holes in a single setup.

13. 13 Laser Drilling Capability is Source Dependent Throughputholes/secondminutes/hole Feature sizef (wavelength, lens focal length, beam diameter, beam quality) Debris10’s µmnegligible HAZ/recasttens to hundreds µmless than 10 µm Depth controlinversely related to removal rate Mechanism

14. 14 Automation of Setup and Drilling Objective – Develop vision and probing tools to gauge the shape and hole location of repaired components. Challenges - Parts are deformed; shape will not match that of the new component. However, the ‘repair holes’ must be coincident with the original holes. Potential return – Improved productivity by automating time-consuming setup steps.

15. 15 In Process Gauging Objective – Actively monitor component airflow to determine which holes should be re-drilled. Challenges – Integration of gauging tools with laser machines. Potential return Higher quality components. Greater machine utilization by avoiding inefficiencies of removing/resetting the part into the drilling system.

16. 16 Summary Improvements in laser drilling technology for modern, new component manufacturing can benefit repair – whether at the repair depot or commercial partner. Additional technology development is needed to improve productivity, reduce dependence on skilled operators, and improve consistency in repair operations. PRIMA North America’s 20+ years history of innovation in lasers for turbine engine manufacturing and repair will reduce risk and cost of these developments.