Laser welding permits joining various types of pieces, made of similar or different alloys, as titanium-based alloys, CoCr alloys, and even AuPd alloys. Laser welding is best suited to weld titanium alloys because they have higher rates of laser beam absorption and lower thermal conductivity compared to other dental casting alloys. Compared to micro pulse welding, laser welding is superior, obtaining the welding cord being faster and easier. The success of the welding procedure depends on the operator’s dexterity and the choice of the welding parameters. Selecting the best combination of pulse energy, pulse duration, and peak power for each welding step is decisive.
Part of the book: Superalloys for Industry Applications
Titanium alloys are considered to be the most advanced materials for orthopedic implants due to the favorable combination of mechanical properties, low density, tissue tolerance, high strength-to-weight ratio, good resistance to corrosion by body fluids, biocompatibility, low density, nonmagnetic properties, and the ability to join with the bone. This is the reason why we decided to assess the resistance of two titanium alloys currently used for orthopedic implants, namely, Ti6Al7Nb and Ti6Al4V, as reference, to cyclic fatigue by dynamic tests with crevice corrosion stimulation. According to the results obtained, the examined electrochemical quantities, the visual and SEM observations, and EDX analysis reveal better corrosion behavior of the prostheses made of Ti6Al4V—anodized series compared to prostheses made of Ti6Al7Nb. The further comparison of two explanted proximal modules, made of Ti6Al7Nb and Ti6Al4V, to the same type of prostheses evaluated by cyclic fatigue dynamic tests with crevice corrosion stimulation reveals that there are significant similarities, in particular with regard to the electrolyte diffusion, deposition of products and corrosion. Cation extraction tests which were carried out for Ti6Al7Nb prostheses that have undergone particular surface treatments show significant differences depending on the surface treatment and demonstrate that orthopedic implant materials are not “inert.”
Part of the book: Engineering Steels and High Entropy-Alloys