11/19/2019|DMG MORI Medical Excellence / ADDITIVE MANUFACTURING

Hip cup from the powder bed

With the powder bed machines of the LASERTEC SLM series, DMG MORI creates efficient process chains for the production of medical technology products.

Additive manufacturing offers almost limitless freedom in design and enables economical handling of often expensive materials. Processes such as the powder bed technology have long since established themselves as an optimal supplement to conventional process chains in machining. More and more medical companies are recognizing and utilizing the potential of this technology. The spectrum of components already ranges from dentures and bone plates to entire implants. DMG MORI accompanies and promotes this development with integrated manufacturing solutions consisting of programming software, powder bed machines of the LASERTEC SLM series and machining centers for precise finishing of medical components. The latest highlight is the production of a hip cup by means of selective laser melting on the LASERTEC 30 DUAL SLM.

The three models of the LASERTEC SLM series, so far, are suitable for very different applications in the medical sector. In the powder bed of the proven LASERTEC 30 SLM 2nd Generation, for example, 32 bone plates for wrist surgery can be set up simultaneously. Finish machining is performed extremely economically on an automated DMP 70. For more precise applications in dental technology, the LASERTEC 12 SLM is the perfect choice. At 35 µm, it has the smallest focus diameter in relation to the size of its build volume. The high surface quality considerably reduces the effort in post-processing. When productivity and build-up rate are paramount, users turn to the LASERTEC 30 DUAL SLM. The larger build volume – 300 x 300 x 300 mm compared to 125 x 125 x 200 mm for the LASERTEC 12 SLM – combined with the newly developed dual-laser optics module reduces the processing time of dental products or implants to a minimum.

Efficient production of customized implants

In the field of 5-axis laser deposition welding DMG MORI will be presenting the new LASERTEC 125 3D hybrid at the formnext, a machine designed for workpieces up to ø 1,250 x 745 mm and 2,000 kg.

Thanks to its two powerful 600 W lasers, whose scan fields each cover the entire build volume, the LASERTEC 30 DUAL SLM allows build rates of over 90 cm³/h. DMG MORI makes use of this in the example of hip cups, for which the machine tool manufacturer has developed a highly productive manufacturing process. “The application is so interesting because the powder bed process offers us the possibility to economically manufacture even individually adapted hip cups,” explains Dr. Uli Sutor, Key Account Medical Industries at DMG MORI, the motivation behind the project.

Since medical technology products such as titanium implants are subject to the highest quality requirements, it was a top priority for DMG MORI to work out an absolutely process-reliable manufacturing process. Dr. Uli Sutor recalls the various tests: “We tested the stability of sample components in the entire build volume and their relative density – especially at higher assembly rates.” With a relative density of over 99.95 percent in the final component, the tests exceeded expectations, and the bending and stress tests were also consistently successful.

Component accuracy was also guaranteed: “The dynamically adjustable focus diameter was further optimized and is now 50 µm. In addition to the high productivity, this results in a very good surface quality. The active liquid cooling ensures outstanding long-term stability in the process. All ingrowth structures can be realized. Dr. Uli Sutor is satisfied with the entire process: “We achieve the best mechanical properties and build-up rates on the market.”

Intelligent software solutions in the additive manufacturing process

The production of hip cups is a holistic process from design and programming, additive manufacturing in a powder bed to final finishing on an NTX 1000 2nd Generation. It is required, for example, for the precision machining of the internal thread. DMG MORI has used OPTOMET as software for the optimization of the parameters in the powder bed process in the product range and also in this project. Dr. Uli Sutor explains: "With it, process parameters can be predicted within a few minutes as well as mechanical properties of the materials.”

CELOS is also an elementary part of the process. The integrated software solution ranges from CAM programming directly at the machine using RDesigner to the control of the two machines. Monitoring tools such as camera-based monitoring of the build-up and coating quality complete the functional scope.

DMG MORI offers TULIP as the third software in the bundle and for simple digitization of production processes. With this software, APPs can be created quickly, intuitively and without programming knowledge. In the field of ADDITIVE MANUFACTURING, the first APPs have already been developed, which enable and simplify the tracking of the powder base material. Thanks to TULIP it is possible to track powder loading, consumables and print jobs at the push of a button. “An APP also simplifies the documentation of maintenance and software updates,” Dr. Uli Sutor adds.

Focus on work safety

Multi-material applications and graded materials can also be realized with the machines of the LASERTEC 3D / 3D hybrid series from DMG MORI.

An essential part of the production concept around the LASERTEC 30 DUAL SLM is safety. The decisive features here are the closed powder circuit and the permanent filter system. The rePLUG powder modules prevent the fine metal powder from escaping into the ambient air. Furthermore, they allow a quick powder change in less than two hours. The permanent filter system also ensures automatic passivation of metal dusts. The filter service life is over 3,500 hours.

Rethinking old processe

The projects in medical technology to date, and in particular the production of individually adapted hip cups, impressively demonstrate that additive manufacturing has arrived in the industry and can still achieve a great deal there. Dr. Uli Sutor is optimistic: “We will keep putting many proven processes to the test and further optimize them with the help of our powder bed machines.”

Contact us for all issues related to the DMG MORI technical press.