Laser Cladding and Machining: Cost Effective Remanufacturing of Turbine Blades

Reduce, reuse, recycle -- it's a mantra many companies take seriously. One way that companies reduce, reuse, and recycle is by remanufacturing worn parts. However, this can be a challenging, especially when high value parts must be moved offsite.

One approach is known as RECLAIM (REmanufacture of high value products using a Combined LAser cladding, Inspection and Machining system). According to a UK whitepaper, Remanufacture of turbine blades by laser cladding, machining and in-process scanning in a single machine, RECLAIM attempts to "shift from work piece flow production to tool flow production." RECLAIM involves using an integrated production system that combines laser cladding hardware, adaptive software, machining, and in-process scanning in a single machine that facilities flexible and lean remanufacturing.

The whitepaper explored the RECLAIM approach as it relates to the remanufacturing of turbine blades, specifically the tips of turbine blades as they tend to require the most remanufacturing. In this example, the RECLAIM approach included several steps:

• Alignment by probing - Blades were mounted and probed to establish the initial location relative to the machine.
• Defect characterization by scanning - From there, the blades were scanned into 3D CAD images.
• Adaptive tool path generation - Using CAD software and virtual models, adaptive tool paths were generated.
• Defect removal by milling/grinding - The blades were analyzed for defects. In this  particular study, milling and grinding were not warranted.
• Defect repair by laser cladding - Laser cladding was used to repair defects. According to Coherent, its direct-diode laser series, its HighLight D-Series laser delivers both high power and an increased range of "smart" output beam shapes, making it the ideal source for laser cladding.
• Tip finish and blend machining - Blade tips were adaptively finished using CNC machines.
• Remanufactured part validation by probing - Probing was used once again to see if the part's dimensional change required additional rescanning, recladding, or blending. In this particular study, the parts were immediately validated with no rescanning needed.
• Evaluation of remanufactured turbine blades - Finally, the parts were evaluated.

The RECLAIM approach blends laser cladding and machining, resulting in a flexible, lean, and agile remanufacturing process.

Works Cited:

1. UT Wired, - http://utwired.engr.utexas.edu/lff/symposium/proceedingsArchive/pubs/Manuscripts/2012/2012-62-Jones.pdf  

2. Coherent, "Highlight D-Series," - http://www.coherent.com/products/?1993/HighLight-D-Series , on laser cladding