New Fe-, Co- or Ni-based alloys for high temperature and/or wear-resistant and mechanical fatigue-resistant applications.
“With permission of TRUMPF Laser- und Systemtechnik GmbH”
Laser Metal Deposition (LMD) is a directed energy deposition (DED) process, which uses a laser source to generate a concentrated beam that melts the material. This is dispensed through a nozzle, thus allowing layer-by-layer additive manufacturing of medium-to-large sized complex shaped parts, with a high deposition rate (up to 2.5 Kg/h).
LORTEK has embraced LMD-powder technology, as there is a wide variety of commercial materials and new improved alloys. This process also permits the manufacture of multi-material or gradual composition parts. One of the advantages of the LMD process is that it allows to control the energy density input through the laser power and beam diameter, to effectively control the heat input per unit of area, and obtain defect-free parts. On the other hand, LMD is quite an efficient process as most of the filler material melts (between 70-90% efficiency), and only the necessary material in the required areas is used, thus reducing waste and allowing parts with near-net-shape to be obtained.
With LMD, it is not only possible to manufacture parts, but also to repair high-value parts and to add features to components manufactured by means of other processes. The combination of LMD and CNC machining has led to new manufacturing possibilities in hybrid machines and multi-process cells, where additive manufacturing processes and subtractive processes are adequately used to manufacture components with excellent surface quality in different areas, such as turbomachinery, aeronautics, automobile industry, wind, oil and gas, among others.
LORTEK's knowledge in materials, metallurgy, advanced characterization and the LMD process, permits 360º accompaniment in specific feasibility studies for each client and sector, supported both financially and technologically for the correct implementation of this disruptive metal additive manufacturing technology.
LORTEK has three solid state laser sources: a 6kW disc laser, a 3kW Nd-YAG laser, and a 1kW fibre laser. It also has a semi-conductor source: a 3kW diode laser. This wide range of wavelengths permits processing a broad gamut of materials, using the most adequate laser for each specific application. It also has different headstocks with fixed and floating optics, which permit varying the laser spot during the process, as well as incorporating ports for on-axis sensors or camera to monitor the melted bath, or to measure the temperature. The laser beam is guided to the headstock by different diameter optical fibres. The powder is provided through powder feeders from two heated hoppers with different types of nozzles: coaxial for fine and standard powder, and three-jet nozzles with carbide inserts for the different applications and degrees of accessibility required. Different specialized CAM software packages are available to generate trajectories for direct deposition processes, in which kinematics virtualization and simulations are possible.
Two LMD workstations are available, depending on the required degrees of freedom for the application:
Challenges to be faced in the coming years: