Direct comparison between Co-28Cr-6Mo alloy prepared by Selective Laser Melting and traditional investment casting

Abstract Thanks to high mechanical properties stable at elevated temperatures, high abrasion resistance, suitable corrosion resistance and biocompatibility, ternary cobalt alloy Co-28Cr-6Mo is a widely used material in the field of aviation industry and medical implants production. Due to the difficult formability and machinability of this alloy in combination with complex shapes of produced parts, investment casting is the mostly employed production process. However, additive manufacturing provides new processing opportunities. E.g. Selective Laser Melting (SLM) technology fusing metallic powders by precisely focused and controlled laser beam enables the production of highly complex parts with high precision. In this contribution, we bring a direct comparison between the microstructures and mechanical properties of Co-28Cr-6Mo alloy prepared by SLM and investment casting. Due to significant differences in microstructure fineness and phase composition, SLM is revealed to increase not only material strength and hardness but concurrently plasticity. As a result of rapid solidification during SLM, very fine cellular microstructure with Mo microsegregation at cell walls is formed without the occurrence of any secondary phases. The distinctive microstructure of the additively manufactured alloy can be expected to be the cause of many other variances in the material behaviour.</jats:p

3D Digitalization of the Human Body for Use in Orthotics and Prosthetics

The motivation of this work was to find a suitable 3D scanner for human body parts digitalization in the field of prosthetics and orthotics. The main project objective is to compare the three hand-held portable scanners (two optical and one laser) and two optical tripod scanners. The comparison was made with respect of scanning detail, simplicity of operation and ability to scan directly on the human body. Testing was carried out on a plaster cast of the upper limb and directly on a few volunteers. The objective monitored parameters were time of digitizing and post-processing of 3D data and resulting visual data quality. Subjectively, it was considered level of usage and handling of the scanner. The new tripod was developed to improve the face scanning conditions. The results provide an overview of the suitability of different types of scanners

3D Topological Scanning and Multi-material Additive Manufacturing for Facial Prosthesis Development

Prosthetic-based rehabilitation is an alternative to and offers several advantages over surgical intervention. Prosthetic devices are commonly handmade, requiring significant amounts of skilled labour and subjective manufacturing techniques. This chapter discusses the use of industrial optical scanning methods to capture the surface topology from a volunteer’s facial anatomy. This data was then used to generate a 3D CAD model, which was further used to design a patient-specific prosthesis. Amongst the many advantages over the existing techniques are that data collection is non-intrusive, quick to collect and provides anatomically precise information. The use of 3D CAD models provides greater flexibility when developing and evaluating design iterations and further allows for the creation of ‘part libraries’ for use where patients have no initial reference anatomy. Such patient data can also be kept on record should it be required for future use. The final prosthesis is realised through high-resolution, multi-material additive manufacturing, providing precise model reproduction and adding functionality such as mimicry of soft and hard tissues. This approach provides an optimised, low-cost method for streamlining similar prosthesis production