Growing Interest in Additive Manufacturing at EMO 2015
“Growing” parts or part features with additive manufacturing processes was a theme at EMO 2015 in Milan, Italy. The small sample that follows is representative of industry's maturing perspective on additive manufacturing.
WFL Millturn Technologies makes some of the largest millturn machines in the world. One advantage of combining milling and turning is not having to move and reclamp large, heavy workpieces. Incorporating a laser head for laser cladding now enables the millturn to build up protruding features and then machine them without re-clamping the workpiece. The laser head (with its nozzle pointing down) is visible on the right in this photo.
The laser head consists of a nozzle that delivers metal powder propelled by an inert gas that also prevents oxidation. The 10 kW laser beam passes through the center of the nozzle and is focused on the area to be clad. Programmed control of the machine's axes produces the desired shape, which can be built up in successive layers.
The workpiece shown by WFL at EMO displayed these laser-clad “additions.” Note that one of the cylindrical protrusions (to the left of a larger feature in its as-clad condition) has been machined in place. The laser head can also be used for welding, curing surface treatments and case hardening, although the appropriate nozzle and lens assembly must be in place, depending on the application
Machine tool builder Ibarmia showed a very different type of machining center (a five-axis, moving column hybrid configuration) that incorporates a laser cladding head. The head can be changed out automatically in the spindle's HSK-style tapered tool interface. The moving column design enables the machine to grow large workpieces on the rotary table (and then machine them in the vertical turning mode). Adding features to existing workpieces clamped to the table is also possible.
This is a titanium alloy bicycle frame in its “larval stage,” so to speak, as produced in one cycle on a Renishaw AM 250 machine. All of the pieces for the frame are formed together as a kit, and then removed from the build base for assembly. This kind of creative thinking in the application of additive processes is what makes this technology fresh and exciting.
The metamorphosis of the titanium alloy frame is complete, giving the assembled bicycle significant advantages in the weight reduction and increased strength.
Also at the Renishaw booth was this example of a 3D printed mold component with conformal cooling lines built in as the part was grown. The internal passages can be viewed as blue strands in the see-through counterpart of this same component.
The value of additive manufacturing for the mold and die industry is certainly well recognized by GF Machining Solutions, which introduced the AgieCharmilles AM S 290 Tooling Additive Manufacturing machine. This powder bed-based machine is a version of the EOS M 290 metal laser sintering system that is customized for integration into automated production of mold inserts and die components.