Introduction
The average power required for these small scale tube cutting applications is in most cases relatively low and is well within the power range of currently available fiber lasers. Certain specialist manufacturers are now starting to offer fully integrated laser cutting systems commercially fitted or retro-fitted with fiber lasers. These systems provide the sophisticated clamping and high accuracy multi-axis movement required for precision cutting of a range of different medical device materials.
Laser Cutting of Steel
Precision cutting of this nature has until recently been performed by flashlamp pumped solid state lasers using co-axial assist gas, usually nitrogen at relatively high pressure and flow rates. In these trials, a SPI 100 watt fiber laser with a single-focus lens configuration was used to generate these samples. To confirm cut quality, samples were prepared for Scanning Electron Microscope (SEM) examination.
Fiber Laser processing results
Fiber lasers can produce very low taper high aspect ratio cuts with very little process optimization. When compared with most solid state YAG lasers, kerf width, cut taper and recast layer thickness can all be significantly reduced.
There is a significant improvement in the controllability of the cut due to the ability to freely modulate the pulse frequency and pulse duration. Visual observations of cut quality has been confirmed and enhanced by metallographic examination of transverse cross sections of laser cuts.
40x nitinol stent cut using SPI fiber laser.
2mm OD, 200 μm wall thickness stainless steel tube.