**7.2 EBM technology**

176 Biomedicine

As shown in the Applications section, EBM technology has proved to be a very powerful tool for manufacturing of high added value products. At the same time, EBM is a relatively recent manufacturing technology (first machine sold in 2002) and has much more room for improvement. For both reasons, there are different R&D attempts being performed along the world in order to obtain new findings applicable to new biomedical implants and for supporting the biomedical industry. These attempts are being performed in different R&D

The following advances are not relevant only for biomedical sector but do offer

In the biomedical field, lots of efforts are being made in order to develop new materials and/or improve material properties (metals and polymers) for biomedical applications. Also, the evolution of manufacturing processes, Coatings and Surface Implant Modification

Nowadays, metals are the best option for long time load-bearing prostheses. For this reason, the development of new metallic biomaterials for long-term prostheses and adequate the manufacturing processes in order to achieve best possible properties is a matter of great

In particular, Titanium alloys are very interesting for research due to its excellent properties such as high corrosion resistance, low modulus, high fatigue strength, low density (lower than most common metallic materials), good mechanical properties, etc. There are two

 *Biocompatibility improvement:* Some attempts are being done for improving traditional Ti6Al4V alloys, i.e. Ti6Al7Nb and Ti5Al2.5 alloys improve material biocompatibility and mechanical properties, substituting Vanadium by Nb or Fe respectively (less toxic). These alloys have similar mechanical properties to traditional Ti6Al4V but providing with higher biocompatibility and slightly lower modulus. (Ratner, 2004), (ASTM, 2010),

 *Lower Modulus*. Beta-type Ti alloys with a low elastic modulus has proved to be effective for inhibiting bone absorption and enhancing bone remodelling. The addition of some alloying elements like Mo, Zr, Ta, etc permits to stabilize the BCC (beta) phase at room temperature. Moreover, it is well known that the Young modulus of β-type Ti alloys are considerably smaller than those of the α- and (α + β)-type Ti alloys. (Ratner, 2004),

Although for the time being these alloys are not commercially available for EBM technology

there are many efforts to adjust the processing parameters (AIMME, 2011).

competitiveness to additive manufacturing of medical implants.

**7. Future developments** 

areas, such as: Materials

Software

**7.1 Materials** 

interest.

EBM Technology

are remarkable areas of work.

relevant areas under development:

(ASTM, 2010), (Niinomi, 2008).

(ASTM, 2010).

As a proof of the improvement potential of this technology, recently a new manufacturing beam strategy named MultiBeam® has been developed and released. This strategy allows EBM to produce finer details and obtain better surface finish, splitting the high energy electron beam in multiple finer beams (less power/beam) so the energy input in every location on each layer can be accurately controlled. MB strategy opens the possibility of manufacturing implants with better surface finish and finer scaffolds (Figure 12). Some attempts with finer beams and powders are being performed in order to achieve higher resolution with the EBM process.
