Flam3D also kicks off the 3D Delta Week this year with the AM R&D Day. Research institutions in the field of additive manufacturing present themselves with their projects; companies can join. There is a lot of research into AM in the Benelux. The Vrije Universiteit Brussel gave a kick-off during the last member event of Flam3D.
The Vrije Universiteit Brussel (VUB) is probably not at the forefront of most people’s minds when asked about a university that is involved in research into additive manufacturing. Nevertheless, the AM Research Group is active, both with metal and polymers. And that for more than 10 years: in 2012 the VUB AM Research Lab started. Among other things, the Brussels researchers want to get 3D metal printing into industry more quickly. Their solution: making smart components with AM, said Professor Dieter De Baere during the Flam3D meeting. Additive manufacturing lends itself like no other technology to the smart integration of sensors.
Measure load on structural parts
An example of this is the eSHM technology, Effective Structural Health Monitoring, developed at the university, which has now been patented. “We integrate a monitoring system into the structural part to monitor the integrity of the part during its life phase.” A capillary is placed in the material at critical places. This is vacuumed. A high-precision pressure sensor is placed on the outside. As soon as it detects a change in pressure, it indicates the formation of micro-cracks in the material that will eventually lead to material fatigue and fracture. “We are working on this with large companies. The system is robust,” says Dieter De Baere. “The data can be interpreted unambiguously.” With this technology, companies can take a step towards predictive maintenance. And without additive manufacturing this would be impossible. “eSHM is only possible with AM. With other techniques this is impossible or at least very difficult.”
The second edition of the Additive Manufacturing R&D Day, part of 3D Delta Week, will take place on 27 March. For a day, researchers exchange information with each other, but also with industry representatives. The aim of this R&D Day, which Flam3D organizes at the Mikrocentrum, is to stimulate cooperation between research centers and with the business community.
Self-developed hybrid AM system
A lot of technology is developed in-house at the VUB. In additive manufacturing, the focus is on DED technology. For example, a proprietary metal AM system has been developed for the investigations. The gantry system allows the production of large components. A number of projects look at how to combine additive and subtractive technology; print only what is really necessary. This hybrid technology is being developed in two projects: HyLaForm and HiPass. This last project is about reducing the roughness of 3D printed parts so that they become more accurate. “If you still want to reach certain locations after printing, a hybrid machine has important advantages,” explains Dieter De Baere. Improving the surface is done with a laser.
Control 10 axes simultaneously
The machine for this has been developed in-house; it is controlled by the Bosch Rexroth MTX control. A total of 10 axes are controlled via the two channels of this control, including the laser that melts the powder. The VUB itself has developed a system to log parameters such as the position of the head, the speed, the laser power, the power consumption of the spindle motor and the torque at a frequency of 2000 samples per second. In this way, a digital dichotomy of each part is created, including the history of the temperature and the geometry. This data is then used to further investigate and improve the process. One of the findings of the Brussels researchers is that the surface improvement also improves the fatigue properties of the material. These improve by about 30%.
Self-healing materials
A third interesting project that the VUB presented during the Flam3D member event is about the use of self-healing plastics. What is special about this is that the plastics form a homogeneous material again at a low temperature, even in the event of serious damage, for example if they are cut in half. Research is also carried out into the corrosion sensitivity of AM workpieces and simulation of AM processes. According to Professor De Baere, the research group is open to collaboration with industry partners.