The medical device industry has created a big demand for laser micro machining. Flashlamp pump solid-state lasers are currently used for this application. Many of these lasers are configured to operate near the diffraction limited beam performance to maintain a very small kerf width. In order to meet yields and up-time requirements reliable laser operation and low maintenance are required. Under production conditions it is a challenge to keep such a laser system performing with the consistency required. The fiber laser concept could provide benefits in order to maintain high up-time and high yields. The single mode fiber laser does not need mirror alignment. Diode pumped fiber lasers also reduce maintenance, as flash-lamp changes are eliminated. The compact air-cooled design also helps to save expensive clean room space on the production floor. Recent improvements in average laser power now make the fiber laser suitable for industrial cutting applications. The focus for this work is therefore laser micro-cutting of stainless steel stent implants and this paper presents the first micro-cutting results in stainless steel. Kerf width and surface quality on the sidewall are of special interest. Also presented are laser operating conditions to minimize Heat Affected Zone (HAZ) in stainless steel.
The process monitoring of the top side and the evaluation of surface quality were applied in adjustable ring mode (ARM) laser welding of 316 stainless steel by using visual monitoring and confocal sensor technology. Experiments were conducted in different power arrangements of an ARM laser. In this study, the process status was evaluated based on the area of keyhole entrance and the width of the pool. The geometric characteristics of the topside weld were measured by a confocal sensor. The shape of the fusion zone was analyzed based on its cross section. The process mechanism of a different mode of ARM laser welding was investigated by analyzing the process status and geometric characteristics of the surface bead. Experimental results showed that dual-mode laser welding could stabilize the keyhole entrance with a uniform weld surface formation in comparison to the pure ring-mode laser weld. The dual-mode laser also generated a wider molten pool with a wider fusion zone than the pure center laser weld.
The fiber laser concept is proven technology for telecom applications where its single mode performance and reliability is essential. Newer generation diode-pumped fiber lasers are using pump diodes especially developed for telecom applications and therefore offer excellent controllability of the laser pulse length and pulse frequency. In recent years the output power of fiber lasers has increased steadily. This high power performance enables the fiber laser to serve industrial applications like marking. High power fiber lasers are now available at power levels sufficient for micro cutting applications. This paper presents micro cutting results with pulsed fiber lasers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.