High-Temp-Alloy

Waspaloy and Rene 41 are nickel-based superalloys used in turbine engines and high-temperature applications. They are among the most difficult materials to deep hole drill. These alloys retain strength at high temperatures, work-harden rapidly, and produce extreme cutting forces. I have drilled both materials for aerospace components. Rene 41 is slightly harder than Waspaloy at room temperature — about 40 HRC versus 38 HRC. Both are unforgiving. Here is what I have learned. ...

Heat management is the main challenge when drilling high-temperature alloys. These materials retain heat at the cutting edge instead of letting it dissipate through the chip. The heat at the cutting edge can exceed 1000 degrees C in the cutting zone. This heat degrades the tool edge rapidly, and once the cutting edge goes, the tool fails within seconds. I’ve learned that the key is removing heat as fast as it is generated. If you let the heat accumulate, the tool fails within seconds. Here is my approach to keeping the cutting zone cool when drilling superalloys like Inconel 718, Waspaloy, and Rene 41. ...