A special processing technique now allows Selective Laser Melting (SLM) to be used with more difficult materials such as magnesium alloys, copper alloys, and other crack-prone, difficult-to-weld metals. The use of these materials makes it possible to employ the SLM process in new application areas. Several examples will be presented in a lecture session at the International Laser Technology Congress AKL’16 and the accompanying “Laser Technology Live” event at the Fraunhofer Institute for Laser Technology ILT.
Selective laser melting with “normal” materials such as stainless steel, aluminum or titanium alloys has already come of age in the world of production. The materials and processes have been extensively researched, and the related machinery is available from a number of vendors.
Picture 1: Implant (scaffold) with defined pore structure made from biodegradable magnesium alloy (WE43). It measures 10x10x7.5 mm³ with a strut thickness of approx. 400 µm.
© Fraunhofer ILT, Aachen, Germany / Volker Lannert.
Things only get difficult when attempting to work with other materials such as Magnesium. It is not only 30% lighter than aluminum, but it can also be used to produce resorbable implants, thus making it extremely desirable for use in lightweight construction and medical technology applications.
Experts at Fraunhofer ILT have developed a processing technique that now makes it possible to work difficult materials using SLM. To combat heavy smoke formation, a new process chamber featuring optimized shielding gas flow was developed in cooperation with ILT spinoff Aconity3D for use with magnesium alloys. In addition, processes for use with copper alloys were optimized, as were special systems with high-temperature preheating for use with crack-prone and difficult-to-weld metals.
SLM allows for bioresorbable magnesium alloy implants
Desirable features of implants, such as tailored designs and complex structures, can be produced at no extra expense using SLM. As a material, magnesium offers the added advantage of being resorbable by the human body. Implants based on solid magnesium materials are already in use, but further benefits are promised for implants with pore structure.
The idea here is that new bony material will grow into the implant, while at the same time the metallic material is resorbed by the body. Fraunhofer ILT has developed an SLM process for magnesium alloy implants of this type, in which both the exact shape and pore size of the implant can be chosen. The biocompatibility of the implant prototypes has already been demonstrated in vitro.
While Fraunhofer ILT continues to research new materials and processes, SLM equipment for magnesium alloys is already available from Aconity3D.
Lighter and stronger: SLM allows for full topology optimization
The advantages of magnesium alloys have long been known in the worlds of aerospace and motorsports. These materials are 30% lighter than aluminum, yet they are also much more difficult to work.
The new SLM processing technique solves this problem in an elegant fashion. To explore the concept in detail, Fraunhofer ILT constructed a motorcycle triple clamp in 1:4 scale, by optimizing the entire topology of the component by computer. The objective here is to achieve full structural and weight optimization for comparable lightweight parts.
This represents one of the world’s first example of complex components made from magnesium alloys. In terms of quality, they are equal to other SLM products, yet with respect to strength they are even superior to cast parts.
This opens the door to new applications not only in lightweight construction, but also in medical technology, such as custom-made surgical bone replacements for cranio maxillofacial applications.
SLM live at AKL’16
In addition to magnesium alloys, research work is continuing on developing SLM for processing novel materials such as high-temperature alloys for turbomachinery applications or copper alloys. The various processes will be exhibited at the International Laser Technology Congress AKL’16 in Aachen.
As a part of the exhibition, Fraunhofer ILT will be once again offering around 70 “Laser Technology Live” presentations in addition to talks with subject area experts at its Application Center.
International Laser Technology Congress AKL’16
April 27-29, 2016
Laser Technology Live
April 27, 2016, 16:30
Fraunhofer Institute for Laser Technology ILT
Dipl.-Phys. Lucas Jauer
Rapid Manufacturing Group
Phone +49 241 8906-360
Dr.-Ing. Wilhelm Meiners
Group Manager Rapid Manufacturing
Phone +49 241 8906-301
Petra Nolis | Fraunhofer-Institut für Lasertechnik ILT
New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State
Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy