Tatu Syvänen

Direct Metal Laser Sintering – New Possibilities in Biomedical Part Manufacturing

Direct Metal Laser Sintering (DMLS) has been utilized for prototype manufacturing of functional metal components for years now. During this period the surface quality, mechanical properties, detail resolution and easiness of the process have been improved to the level suitable for direct production of complex metallic components for various applications. The paper will present the latest DMLS technology utilizing EOSINT M270 laser sintering machine and EOSTYLE support generation software for direct and rapid production of complex shaped metallic components for various purposes. The focus of the presentation will be in rapid manufacturing of customized biomedical implants and surgical devices of the latest stainless steel, titanium and cobalt-chromium-molybdenum alloys. In addition to biomedical applications, other application areas where complex metallic parts with stringent requirements are being needed will be presented.

Diode pumped fiber laser in direct metal laser sintering (DMLS) process

Direct Metal Laser Sintering (DMLS) is a layered process that enables the fabrication of complex net-shape mold inserts and metal components directly from 3D CAD data. The new generation machine EOSINT M270 was announced late 2003 and introduced to the market in 2004. The main difference compared to the previous generation machine EOSINT M250 Xtended is the new type of diode pumped fiber laser with very good beam characteristics. The new solid-state laser has made a smaller laser beam spot size possible, which allows precise processing of very fine details. The absorption of laser energy into the metal powder has also improved due to the shorter wavelength.This paper presents the effects of the new solid-state fiber laser on the DMLS process, material characteristics of sintered metals and comparisons to the previous DMLS process using traditional CO2 laser.Direct Metal Laser Sintering (DMLS) is a layered process that enables the fabrication of complex net-shape mold inserts and metal components directly from 3D CAD data. The new generation machine EOSINT M270 was announced late 2003 and introduced to the market in 2004. The main difference compared to the previous generation machine EOSINT M250 Xtended is the new type of diode pumped fiber laser with very good beam characteristics. The new solid-state laser has made a smaller laser beam spot size possible, which allows precise processing of very fine details. The absorption of laser energy into the metal powder has also improved due to the shorter wavelength.This paper presents the effects of the new solid-state fiber laser on the DMLS process, material characteristics of sintered metals and comparisons to the previous DMLS process using traditional CO2 laser.

Dimensionally Accurate Mold Inserts and Metal Components by Direct Metal Laser Sintering

One of the main deficiencies in today‘s rapid tooling techniques is the capability of producing only near net-shape parts. Direct Metal Laser Sintering (DMLS) is a technique that enables the fabrication of true net-shape parts in just a few hours with only minimum postprocessing. The DMLS is a laser-based rapid tooling process developed in Europe by Rapid Product Innovations (formerly Electrolux Rapid Development Finland) and EOS GmbH Germany. Rapid Product Innovations was also the first to implement this technology to functional prototyping by using two proprietary bronze-based powders and a new steel-based powder. The technique enables the fabrication of tailored microstructures from porous matrix to near full density. Thus, functionally gradient structures can be fabricated, i.e. material is sintered to full density only where it is needed. This paper describes the philosophy of fabricating true net-shape mold inserts and metal components, but also concentrates on how to maintain the dimensional accuracy even after the post-processing. The study shows that even +/− 0.05 mm accuracy can be obtained. The results of the study also illustrate the beneficial effects of reduced layer thickness and post-processing on the surface roughness and mechanical properties as well as the suitability of various conventional and non-conventional coatings. With reduced layer thickness, the step-shaped effect of the layers was no longer visible. The surface was even further improved by shot peening and coating. In addition, case studies from injection molding, pressure die-casting and direct metal component fabrication are presented.

Preliminary characterization of phenomena occurring during single track fabrication in laser additive manufacturing of stainless steel

Laser additive manufacturing (LAM) is a layer wise fabrication technology which enables the production of complex shaped, individually designed parts with mechanical properties comparable to conventionally manufactured parts. However, the part manufacturing is relatively slow and via this whole production feasibility is not yet totally studied for real series production, as findings from literature shows. It is obvious that many of those studies are carried out in companies “behind locked doors” and because of this whole era of research is suffering of this lack of information.Even though the throughput time from idea to real metal product is short, the throughput time of the actual LAM phase could still be improved to gain more feasible fabrication method. Due to this, it is necessary to increase the build rate in order to improve the process efficiency and also improve whole production feasibility of LAM. It was observed that there are only few public studies about process efficiency of laser additive m...