Laser Processing
- Laser cutting of wine glasses using a 1.5 kW CO2 laser. The glass is between 0.5-1 mm thick. Cutting such products with the laser leaves the desired rounded lip to the glass. Cutting process is a mechanically-induced controlled thermal fracture.
- Hardening of steel axles, using a 2.8 kW high-power diode laser. The surface hardening process relies upon a thermally induced phase change in iron alloys with significant carbon content. The appeal of transformation hardening by laser is the fact that one can direct the laser to harden only the regions desired - leaving the bulk material less brittle. The laser applies far less total heat than other thermal hardening and is almost instant as the part being hardened self-quenches.
- Brazing/silver soldering using a 1 kW high-power diode laser. Brazing can be an effective means of creating and attractive metal bond. The laser applies the minimum necessary heat directly to the area required.
- Cutting hydroformed parts, 1-4 kW diode pumped Nd:YAG laser. Solid state lasers can be fibre-delivered, making them ideal for robot delivery.
- Cutting B-Pillars, 1-4 kW disc laser. Owing to excellent beam quality, disc lasers can be delivered down small fibres (200 μm), making them ideal for robot delivery for cutting applications.
- Cleaning railway lines, using 2 kW Q-switched Nd:YAG laser. The robust and unique, 2 kW Q-switched YAG laser has been mounted onto a specially developed railway carriage, designed to clean debris from both tracks as the train travels down them at up to 40mph. Debris is normally leaf residue crushed to a Teflon-like thin layer, but could also be oil or other debris.
- Metal cutting, with DC025 Slab CO2, power 2.5 kW. Oxygen gas is injected via the cutting nozzle, the exothermic oxidation facilitates faster cutting.
- Remote welding of car seat, The Remote Welding System takes advantage of the superior beam quality of their patented Slab CO2 laser. Remote welding uses a gimbal-mounted mirror to deflect the beam into any position in the focal plane under software control. Spot, seam and stitch welds can be accomplished with negligible time wasted repositioning the laser or part. As a consequence remote welding can achieve far higher throughputs for some geometries.
Marking
- Marking coated metal clip. Permanent marking with a compact enclosure. Video shows a mountaineering clip receiving a decorative mark by selective removal of black coating.
- Marking automotive labels. The labels are permanently marked as well as cut into the desired shape using the laser. These special materials have two properties that make them interesting in automotive, electronics and security fields: they cure upon adhesion so that they are tamper-evident (cannot be removed without destroying) and they can withstand weathering/high temperatures.
Small Components
- 5-axis cutting of medical devices using 300 W pulsed Nd:YAG, stainless steel medical equipment. Nitrogen is injected via the cutting nozzle to minimise discolouration due to oxidation.
- Small mould tool manufacture from tool steel blank directly from CAD design by laser micro erosion using Q-switched YAG laser (~100 W). the laser is delivered via galvanometer scanners and removes material layer-by-layer to generate up the 3D cavity designed. Depth dimensional feedback is shown periodically using a probe. Removal is highest quality at lowest volumetric removal rates at lower pulse energies - here, the material removal mechanism is mainly vaporisation. Removal is lower quality at higher volumetric removal rates at higher pulse energies - here, the material removal mechanism is mainly melt removal.
- Microelectronics. Pulsed YAG cutting / scribing of ceramics, various ceramics, particularly Si wafers and alumina.
- High speed paper/plastic perforation using CO2 lasers This system is capable at perforating filter tipping paper at a rate of half a million holes per second. A more recent application is perforating plastic film food wrapping material to extend the shelf life of produce as a result of improved breathability.
- Plastic welding using direct diode lasers. Other than for thin films, lasers generally weld plastic by transmission welding. The process relies upon ensuring that the top plastic surface transmits the laser wavelength chosen for the job (most natural plastics do) and the lower surface absorbs it (often easy to attain with simple pigments or additives like carbon black). The laser then heats only the interface, producing a smooth, clean and strong weld.
- Plastic welding using YAG or diode lasers. Other than for thin films, lasers generally weld plastic by transmission welding. The process relies upon ensuring that the top plastic surface transmits the laser wavelength chosen for the job (most natural plastics do) and the lower surface absorbs it (often easy to attain with simple pigments or additives like carbon black). The laser then heats only the interface, producing a smooth, clean and strong weld. This video shows a quasi-simultaneous weld technique using the PolyScan system; galvo's deliver the beam repeatedly at high speed over the geometry desired. The entire weld length is bonded in one operation simultaneously.
- Stents: fine tube cutting using pulsed YAG or fibre lasers. Stainless steel and nitinol, typically 0.3 - 5 mm diameter. Stents and other tubular medical devices such as guidewires require very fine detail cutting from blank tube. He video shows designs being cut from approximately 1 mm diameter tubes using a pulsed Nd:YAG. Kerf widths down to about 12 μm are feasible.
- Steel: the video shows the application of a vision system to follow a seam and produce a seam weld using overlapping laser pulses from a pulsed Nd:YAG laser lead frame cutting with pulsed YAG.
- Steel: : the video shows the build up of a surface weld for mould tool repair using overlapping laser pulses from a pulsed Nd:YAG laser
- Steel and other metals. The video shows how galvo beam delivery of a pulsed Nd:YAG laser essentially eliminates time wasted reposition between consecutive welds.
- Packaging plastics: the video shows 3 different cutting/scribing operations performed on a reel-to-reel web of packaging material. Lasers make packaging easy-open.
- Disc lasers for glass cutting. Multiple laser beam absorption is an innovative means of laser cutting glass. A reflector is used to retransmit the approximately 1 μm wavelength beam repeatedly through the glass to create a thermal stress. The beam is used to propagate an initiated crack through the glass in the shape desired. The result is a zero kerf clean, polished cut.
Acknowledgement
The movies and associated information have been provided by Rofin-Baasel UK Ltd. for educational purposes, through the good offices of Andrew B. May.
