30% of emissions in the European Union (EU) originate from transport, and there are commitments by all sectors involved, road transport, civil aviation and maritime for a progressive reduction. The mass of the vehicles has a significant influence on their consumption and emissions, so there is a need to replace traditional heavy materials with light structural materials or combinations of them, and to optimise their manufacturing processes. This work reviews the scientific literature published during the period 2015-19. Aiming to select the most relevant articles minimizing the bias, a search strategy is defined, applied in the Web of Science database, and the selection limited to publications in Open Access, English, Q1-Q2 journals or prestigious conference proceedings, from 01/01/2015 to 01/01/2020. The final objective of the work is to provide a global perspective of the latest trends in studies on light structural materials with application in the aeronautical and/or automotive fields, of studies oriented towards sustainability, and with a special interest in those that apply advanced manufacturing and/or machining processes.

This paper investigates the extrusion force and damage induced during an extrusion process to manufacture bimetallic cylinders combining a titanium alloy sleeve (Ti6Al4V) and a magnesium alloy core (AZ31B). A study has been carried out to determine the damage factor distribution through the extrusion process and how this factor together with the extrusion force are influenced by the manufacturing parameters (extrusion ratio, friction and die semi-angle) by means of finite element (FE) simulations. Also, a Taguchi Design of Experiments (DoE) and an Analysis of Variance (ANOVA) have been performed in order to study the influence of each parameter to minimize the extrusion force needed to perform the process and the damage in the extrudate. The results show that damage distribution in the sleeve does not follow any pattern, appearing in different region in a random way. However, in the core the damage always occurs in the region outside the contour of the sleeve, where it reaches the maximum value and afterwards remains stationary during the rest of the process. In the core, damage increases as friction factor does and it is independent of the cross-section reduction for low die semi-angles (15°) and reaches the maximum values for 60° die semi-angle. In both cases, damage and extrusion force, the more relevant factor to obtain minimum values is the die semi-angle.

In Engineering Schools, metal forming teaching laboratories are not always equipped with all the suitable equipment to show the students how metal forming operations are performed in industrial facilities, due mainly to space and/or economical limitations. In this work, a proposal of design and fabrication of prototype of extrusion equipment is presented, mainly for teaching purposes, but also, for research activities in extrusion processes. To reach the aim, the components of the prototype are integrated in a universal testing machine Hoytom HM-100kN. This kind of equipment is available in any Engineering School, which makes the proposal accessible to any lecturer interested in metal forming teaching. The final design of the prototype was made taking into account the possibility of using standardized components to facilitate both installation and maintenance tasks. It is also important to emphasize the modular nature of the design to allow its adaptation to different applications and case studies. The prototype presented has demonstrated to be able to produce long profiles by cold extrusion, not only with plasticine (typically used in physical modelling) but with a metallic material, as tin. This prototype could be used as an example of extrusion equipment to be reproducible in metal forming laboratories of other universities.