Femtosecond & fiber laser cutting process exploration and HAZ testing

Femtosecond lasers are becoming a more common processing tool for nitinol stents in the medical device industry. Femtosecond and traditional thermal laser (fiber) cutting process windows were explored. Microstructure including heat affected zone (HAZ) was characterized with electron channeling contrast imaging (ECCI) throughout the process window for both femtosecond and traditional cutting methodologies. A unique laser altered microstructure was created with the femtosecond laser cutting process in contrast the typical recast, dross and HAZ microstructures seen with fiber laser cutting. Additionally, HAZ was detected within the femtosecond laser cutting processing window. Several validation considerations for femtosecond and fiber laser cutting processes are summarized.