Joining mechanisms and mechanical properties of PA-Al composites obtained by Selective Laser Sintering

Innovative metal-polymer composites for Selective Laser Sintering (SLS) have been recently developed, characterized by high mechanical performances and high surface quality after finishing. An example is the polyamide-aluminium composite Alumide, suitable for functional prototypes as well as for Rapid Tooling and Rapid Manufacturing applications. The great advantages, in terms of reduced times and costs for the product launching, can be properly exploited only through a deep knowledge concerning the parts performances as a function of the construction process. The present research aimed at overcoming the trial-and-error approach diffused in industrial practice and filling a gap in existing literature. An accurate characterization has been carried out of PA-Al composite parts produced by SLS, investigating the effect of the manufacturing anisotropy on the mechanical performances, both in terms of additive construction and laser sintering strategy. The accurate observation of the joining and failure micromechanisms allowed accounting for the anisotropy of the macroscopic characteristics, developing an original model for the interpretation of the consolidation phenomena and mechanical behaviour.