In times of ever shorter product life cycles and increasingly complex parts produced in ever smaller production runs, additive manufacturing processes can help companies produce new innovative products more quickly. The unique combination of laser deposition welding, combined in a milling machine, gives the user completely new possibilities of application and geometries. The LASERTEC 65 3D offers a hybrid solution for combined additive manufacture and 5-axis milling. This process for deposition uses a co-axial powder nozzle for the additive process. On larger components, the process can be over 10 times faster than the generation with a powder bed machine.
The market for additive processes has grown rapidly in the past years. However, up to now these processes have been restricted to the production of prototypes and small complex parts. Such parts would not otherwise have been manufactured using conventional methods. The combination of metal deposition and metal removal on one machine complements one another. The processes enhances traditional machining methods.
To enable generative manufacturing, the LASERTEC 65 3D is equipped with a 2kW diode laser for laser deposition welding. On the same machine the fully fledged 5-axis milling machine, based on the robust monoBLOCK® design, also makes it possible to carry out highly accurate milling operations. “Thanks to the fully automatic changeover between milling and laser operation, the LASERTEC 65 3D is suitable for the complete machining of complex components, even with undercuts. It can be also used for repair work, the application of various coatings, for mould making, aerospace or even medical engineering”, explains Friedemann Lell the Sales Director for the LASERTEC products at SAUER GmbH.
Producing large parts additively
In contrast to laser melting in a powder bed, laser deposition welding enables large parts to be built using a metal powder nozzle. With a deposition rate of up to 1 kg/h, this process is up to 10 times faster than the laser generation of parts with a powder bed. The combination with milling opens up completely new possibilities. The component can be built up in several steps. The building process can be alternated with milling operations. Therefore it is possible build parts with features that are machined in the middle of the building process. These features would not be normally be possible to reach afterwards with a milling cutter. This can give parts additional functionality, or enables the combination of more parts into a single module.
“In the case of structural components, where today 95 % of the material is removed by milling, with additive processes material is only built up where it is needed. This leads to significant savings in raw materials and costs”, explains Lell.
The complete laser additive head, complete with powder deposition head and cooling, is attached into the standard HSK toolholder of the milling spindle. The additive head can be automatically parked outside the working area in a secure station while milling operations are being carried out in the working area of the machine. The machine and process are operated and controlled by means of the new DMG MORI CELOS operating panel which is combined with the SIEMENS 840D solutionline.Operate CNC control.
Production of 3D contours
Using a diode laser source to the metal powder is welded in layers onto a base. The metal powder forms a high-strength welded bond with the base surface. The welding fuses the material without pores or cracks to form a 99.95% dense deposited material. The coaxial nozzle which combines the laser beam and trasnports the powder with an inert gas, which at the same time prevents oxidation during the build-up process. After cooling, a layer of metal forms which can be machined mechanically.
As laser deposition welding has long been established as a stand-alone technology, it is ideal for incorporation into DMG MORI’s high-quality CNC machines. “The combination of chip-removal and additive processes will become more important in future, as it opens up so many new possibilities for the user”, says Lell.
One strength of this process is the option to successively build up layers of materials in lines of 1.6 mm or 3 mm are possible, depending on the nozzle geometry. The machine can also be filled with two different materials. With a changeover that takes a few minutes, two different materials can be deposited after one another.
Another very important area of application is adding material to an existing part or body. This can be in order to customise, add functionality, features or react to product changes. The machine has the special capability to add material onto an existing 3D surface. Therefore it is not always that a complete part has to be made, but add value to something existing.
Economical solution
Large machines, such as those used for machining bulky components in the energy or aerospace industries, tend to be expensive. So the possibility of carrying out roughing, deposition and finishing on a single machine therefore represents a financially advantageous solution for the customer. Another example here is the energy and oil industry where components often have to be coated with corrosion-resistant alloys to protect them against wear. Deposition welding provides protection for products such as pipes, fittings, flanges and special components which are used in aggressive environments. With a hybrid solution, machining of the base material, coating and finishing can be carried out on one machine. This results in cost savings and a reduction in floor to floor times.
Highlights of the LASERTEC 65 3D
- Intelligent combination of laser deposition and milling enables best surface finish and component precision
- Laser deposition welding with powder nozzle: up to 10 x faster than the powder bed processes
- Feasibility of complete 3D components with diameters up to 500 mm without any supporting geometry, even with overhanging contours
- Direct machining of areas that are no longer accessible on the finished part
- Adding material to existing parts