Aerospace 3D Printing We know the entire weld p

Aerospace 3D Printing

We know the entire weld pool needs to change phase and GE Aviation worries about porosity from unmelted metal powder:

http://www.industrial-lasers.com/articles/pri...ation.html

This is why acoustic emissions is used in the welding community. It is a reliable signal, penetrates the melt pool, and delineate information on phase change:

http://jjsigmalabsblog.blogspot.com/2013/12/a...nergy.html

An independent study, and one that includes the use of an optical sensor, which is similar to PrintRite3D technique confirms the reliability and accuracy of acoustic energy and optical sensing:

http://jjsigmalabsblog.blogspot.com/2014/02/p...and_7.html

The complexity in design of PrintRite3D is in the use of acoustic, optical, and thermal information for automated control:

http://jjsigmalabsblog.blogspot.com/2013/11/r...ce-by.html

This is the same automation Joris Peels and EOS is wanting and trying to achieve:

http://www.tctmagazine.com/blogs/guest-column...p-control/

http://voxelfab.com/blog/2013/12/richemont-an...tch-cases/

Joris Peels, 3D Printing Consultant at VoxelFab, writes extensively on the importance of the closed-loop. He writes, “Scanning and building, plowing through the powder bed, no closed loop control. When exactly does the AM machine realise it has a failed build?” He goes on to say in another article, “There is no closed loop control on the machines and no automated processes for checking part accuracy after production. Often parts have to be hardened, smoothed and post processed sometimes with as many as five different steps on five or more machines. This entire process will have to be automated in order for 3D printing to really work as a metal manufacturing technology.”

EOS: http://www.tctmagazine.com/additive-manufactu...age-5.html

At the moment a feedback system to interfere with the build to recognise and correct errors automatically during the cycle is in development. The ability to review a build and identify errors in the process, however, will be invaluable for QA/QC purposes and process refinement.