Microsecond fiber and pulsed Nd:YAG lasers have been used successfully for hypo tube and stent cutting for many years. The only downside is that cut parts often require a number of post processing operations, depending on material and part requirements. These additional manufacturing steps can add significant cost; they also add to the handling logistics burden for what, in many cases, are mechanically delicate parts, not to mention the added problem of having to deal with chemical-based processes and the disposal of hazardous waste.
Along comes the ultrashort femtosecond (fs) laser, which produces pulses that are shorter than the conduction time for metals. This means that the laser process occurs without a thermal fingerprint on the part. More specifically, a disk-based femtosecond laser offers sub-400fs pulses plus best in class beam quality and peak power that enable the highest quality cold ablation cutting process. Since the cutting process is purely ablation rather than melt ejection, the resulting cut requires minimal post processing, even for materials like nitinol.
When investigating the ROI for a disk femtosecond laser tube cutting system compared to a microsecond system, key considerations are;
- Cutting time per part
- Post processing required
If you look purely at the numbers, a disk femtosecond laser with 5-10W average power and pulse energies around 40 mJ would seem to be under-powered to compete on speed and therefore price per part. But, in reality, when viewing the complete picture of overall part cost, the ROI justification for the disk femtosecond laser can, in many cases, be less than 12 months.