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Biomaterial-tissue interactions are known to largely affect implant performance, relating to alteration of physiological processes. Within this context, metals continue to have a major role as most implants contain at least one metallic part. In particular, titanium alloys are of pivotal importance in orthopedics and dentistry. Being osteointegration somewhat affected by implant surface conditions, surface modifications, surface modification qualify as a way to modulate tissue response, net of an effective design of the whole implant. Currently, a lack of full understanding on the direction to be taken for proper techniques and process conditions to be employed, for the regulation of osteointegration, can be recognized; this happens as a result of the inherent complexity involving host response, implant location as well as its surface chemistry, tomography, stiffness and so on. This short review focuses on one of the most used titanium alloys, namely Ti6Al4V. An overview of viable surface modification processes studied in view of bone cell response, as a way to predict implant performance, will be provided, together with the most recent research findings towards a new generation of biomedical implants.

Nowadays, the manufacturing research efforts have to be conceived in such a way that the product performance criteria are achieved in a lightweighting design concept. Taking these extensions to their extreme, the material properties and the manufacturing solutions have to be considered together in a revolutionary body concept, which should result in an ideal sight to the use of the most performing material in the right place depending on the product requirements. Polymer matrix composites (PMCs) belong to this new material category. The development of joining techniques available to connect PMCs and lightweight alloys has been considered as a key enabling solution in making innovative and sustainable products. The goal of obtaining high joint efficiency must face two main problems, i.e. to deal with the polymeric matrices to get mechanical, physical and chemical compatibilities and to attain or preserve the integrity of reinforcements across the joints customizing the fiber distribution in the joining area. The understanding of current and emerging joining technologies, e.g. the friction stir based techniques, with an optimization of the process parameters needs performant numerical tools to be employed, efficiently. In the work herein proposed, a polymeric base plate was joined to an aluminum alloy part simulating the friction lap joint sequences. Numerical tests have been set by a commercial FE code (DEFORM 2DTM) and a DoE, generated using hypercube sampling, was defined to perform a sensitivity analysis of specific investigated variables on some process outputs.