3D Printing ProcessesAdditive ManufacturingAM Research

Fraunhofer ILT Improves QA On Metal Laser Deposition (DED) Process

Stay up to date with everything that is happening in the wonderful world of AM via our LinkedIn community.

The Fraunhofer Institute for Laser Technology ILT has developed an inline system for testing, qualifying and adjusting the focused powder jet of the nozzles of laser metal deposition machines. With this system, nozzles can be certified and the caustic characterized completely. The user can also visualize and monitor the process thanks to the camera module with integrated illumination.

Laser Material Deposition has already proven itself in various areas – for example when repairing tools or applying anti-corrosion coatings. But the result depends considerably on how evenly the laser beam applies the powder since it is difficult to optimally adjust the process parameters, such as the speed and volume of the powder feed into the melt pool, which plays a decisive role. Before the process, nozzles and caustics must, therefore, be regularly checked, certified and calibrated. But the sequence of these steps has been very complex and cumbersome.

“An employee generally applies a powder trace on a metal sheet, which wis then checked by an expert. But only a few specialists can perform this task in reproducible quality”.

Oliver Nottrodt, project manager for Process Control and System Technology at Fraunhofer ILT

Integration in common systems

© Photo Fraunhofer ILT, Aachen, Germany.The new system for measuring the powder jet.

This unsatisfactory situation motivated the Aachen engineers to develop a machine-supported inline process. The system solution consists of three main components: a camera module along with movable optics and illumination, all of which are mounted on the machining head. The nozzle is measured with a laser module, which is placed in the system. The control of these two modules is provided by electronics integrated either in a separate or the machine control cabinet. Nottrodt explains “For the documentation, it is important to know where the axes of the system are located. Their exact position can be transferred from the basic machine via common data bus interfaces”.

In order to detect and measure the particle density distribution and caustics of the powder jet, the jet is illuminated with a laser line perpendicular to the powder gas flow and observed by the coaxially arranged camera through the powder nozzle. The system changes the relative position of the laser and the machining head several times for further measurements. Finally, the evaluation of 2,000 to 3,000 images shows the statistical distribution of the particles in one plane.

“If I use this method to gradually capture the so-called caustics – i.e. the focusing area in which the powder particle beam is bundled – it can be calculated and characterized very precisely in terms of the most important parameters, such as the minimum diameter and the density distribution”, explains Nottrodt.

Measuring system supports the work of the user

The measuring system enables a user to measure and certify the powder feed nozzles and completely characterize the respective powder jet. It also helps set up the process by taking over a multitude of tasks from the user – such as measuring and marking the positions of the processing laser as well as documenting all work steps. Furthermore, the measuring system uses the geometric characteristics of the melt pool to monitor the laser metal deposition process, which it also visualizes and documents.

Research
Composites AM 2024

746 composites AM companies individually surveyed and studied. Core composites AM market generated over $785 million in 2023. Market expected to grow to $7.8 billion by 2033 at 25.8% CAGR. This new...

VoxelMatters

VoxelMatters is the online trade media portal published by 3dpbm, a leading marketing and market research firm specializing in the AM industry. 3dpbm also publishes the 3D Printing Business Directory, the AM Focus eBook series and the 3dpbm Research AM Market Reports. 3D Printing Media Network was founded with the goal to provide the latest industry news, insights and opinions to a global audience of professionals and decision makers.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button
Close Popup
Privacy Settings saved!
Privacy Settings

When you visit any web site, it may store or retrieve information on your browser, mostly in the form of cookies. Control your personal Cookie Services here.

These cookies are necessary for the website to function and cannot be switched off in our systems.

Technical Cookies
In order to use this website we use the following technically required cookies
  • PHPSESSID
  • wordpress_test_cookie
  • wordpress_logged_in_
  • wordpress_sec

Decline all Services
Save
Accept all Services

Newsletter

Join our 12,000+ Professional community and get weekly AM industry insights straight to your inbox. Our editor-curated newsletter equips executives, engineers, and end-users with crucial updates, helping you stay ahead.