Specialist in 3D metal printing with laser powder fusion technology (DMLS), German EOS presented at the Paris Air Show 2017 its M 290 printer equipped Of a non-destructive control system. The aim is to control the manufacturing quality of the part throughout the process, layer by layer in order to interrupt production if the expected quality is not there and, from 2018, to correct the defects.
A 3D metal printer that detects manufacturing defects itself
“In the aeronautical sector, frequent non-destructive testing is carried out after the manufacture of a part to verify that it has been correctly produced. The idea is to integrate the control methodology during the manufacturing process itself. “ explains Frédéric Verlon, key account manager for the EOS aerospace market. In the first phase, EOS has developed algorithms that monitor the machine parameters related to manufacturing. These are the power of the laser, the temperature of the heating plate, the gas flow, the oxygen content of the manufacturing chamber, and so on. At the same time, the 3D printer designer has developed measuring devices to equip its machines, including optical sensors that analyze the light emitted by the interaction between the laser and the material. “We launched a first system last year that analyzes the energy emitted by the melting bath and we launch at Le Bourget an optical tomography system that is based on a CMOS camera near infrared and monitors the Printing at a rate of 10 frames per second. “ The precision of the device presented at Bourget is of the order of one hundredth of a micron, and the analysis of the part being produced is presented on the screen of which the printer is equipped but also on an application mobile. A production manager can therefore follow the operation of a machine park of his workshop from his tablet and have a state of production in short without having to move. “These are production machines. We are no longer in the field of prototyping or laboratory tests, integrating tomography into the machine, we no longer have to send the piece and wait until a laboratory sends its results “ adds the expert.
A control system that will soon be pro-active
The device is currently equipped with the M 290, and the M 400, the biggest model of the range of 3D metal printers of EOS will in turn have it in 2018. The engineers of EOS does not stop there . “The current version of the software is open loop: it informs the user who will decide what to do. The data are analyzed via algorithms that are able to tell if there are porosities in the room, lack of fusion. A complete mapping of the part is available and the acceptance criteria of the part in the machine are programmed, a default rate. The machine can then generate a warning when the set threshold is reached, or an alarm in order to stop the manufacture of the part. We are working today on a closed loop where the parameters of the machine could be modified during production to correct a defect observed the next layer. It is still at the development stage, with the objective of proposing it next year. “</ Em>
That EOS has presented this device on the Paris Air Show is not a coincidence. The aeronautics sector is very demanding this type of approach because of the quality standards, but Frédéric Verlon believes that the medical sector will also be very demanding of this approach, as well as all industries demanding high level of quality .