Additive manufacturing is getting a lot of air play now with companies using it for applications from rapid prototyping to manufacturing field ready parts. Depending on the intended application a part made using additive manufacturing may require post processing to provide a suitable finish for the application. In additive manufacturing using metals this would typically include machining to create faces ready to mate to other components.
In this video DMG Mori have created a machine to hybridised additive manufacturing with subtractive manufacturing for making metal parts (translations of some of the key captions are below). The additive part of the process uses laser metal deposition to build up material and the video shows a cross-section of the laser deposition head. The machine can switch between the laser deposition unit and a milling spindle on the three axis head while the table has two axis for rotation to make for significant flexibility in the work this machine can undertake. The milling head is capable of milling and drilling operation depending on the tool used.
As the video shows a significant feature of this hybrid system is the ability to switch between additive and subtractive processes. This means the machine can do some of the material removal part way through building up the part which would have otherwise required changing to a stand alone machining centre and more steps to finish the part if the entire additive process was completed in the first step.
The part shown in the video takes a total of 230 minutes of laser metal deposition to complete which DMG Mori claim is 20 times faster than user a powder bed type laser sintering process.The machining takes an additional 76 minutes for a total time a just over 5 hours to complete the part. I am not an expert in machining but I would suggest this is faster than machining the whole part from billet. I also believe the metal’s grain structure from this process would be better than a billet machining according to other information I have seen on laser metal deposition and selective laser sintering.
I have seen how the use of additive manufacture is helping low volume industries such as the aircraft manufacturers make production parts. Where do you think this hybrid additive and subtractive machine system could be used? Would it be useful for plastics or other materials to have hybrid manufacturing systems like this?
Translations of some key captions:
- Vollautomatisches einwechseln des laserkopfes = fully automatic replacement of the laser head
- mit Pulverdüse via HSK-Schnittstelle = with powder nozzle via HSK interface
- laserdüse = laser nozzle
- laserstrahl = laser beam
- träger-/schutzgas = carrier-/inert gas
- metall-pulver = metal powder
- Komplettbearbeitung = complete machining
- mit vollautomatischem Wechsel zwischen Laser- und Fräsbetrieb = with fully automatic switching between laser and milling
- Direkte Bearbeitung von Bauteilsegmenten = Direct machining of component segments
- welche am Fertigteil nicht mehr erreichbar sind = which are no longer accessible on the finished part
- Fortsetzung des Zylinderaufbaus = Continuation of the cylinder assembly
- mit anschließendem Generieren eines konischen Trichters = followed by generation of a conical funnel