We cut precision stainless steel and nitinol tube using our Nd-YAG fibre laser. The parallel coherent light from the laser is focussed onto a spot approximately 0.020mm diameter. Metal vaporises within the diameter of this spot, creating a “hole”. By moving the tube, both rotating it and moving it along X and Y axes, a highly accurate pattern is cut into the wall of the tube. This pattern can consist of holes, slots or can simply mean that the tube is parted off.
Advantages of laser cutting over the alternatives of abrasive cutting and EDM applications are the speed and non-contact nature of laser cutting. Additionally, highly accurate and complex holes and other features can be cut into the tube.
Tubes in the range of diameters between 0.4mm and 30mm and wall thicknesses from 0.1mm to 0.5mm can be cut.
Examples of applications are stents, needles for ophthalmic applications; drug-delivery and special needles can be cut. Spring forms can be made by cutting a spiral along the tube. Stents for use in medical devices are commonly made from nitinol (nickel-titanium alloy) using this laser cutting process, so that a burr-free, precision cut is produced.
Laser marking on tubes and off-axis laser cutting of tubes is also offered by Attica.
Specialist high-frequency pico-second lasers are now being developed which can cut through metal and ceramic materials without leaving a heat-affected zone, so that the surface around the cut no longer requires post-finishing such as pickling or polishing.
Alternative methods of metal cutting include EDM, or electro-discharge machining. This method uses a wire electrode to oxidise and remove metal, with the part immersed in aqueous fluid, and provides an alternative very accurate cutting method. Irregular metal shapes such as gears can be cut by EDM wire erosion. Precision tube cutting, without burrs at the tube ends, can also be carried out using this method, in place of the more usual laser cutting or abrasive cut methods.