Suchergebnisse

Porous structures have unique physical properties(mechanical, density, etc.) that are related to their low density and architecture. These properties open a wide range of potential applications, such as biomedical, packaging, thermal insulation, filtering, food and beverage, pharmaceuticals, automobile, military and aerospace industries [1]. Laser Sintering is an additive manufacturing method that offers many advantages over conventional manufacturing techniques of porous structures with well-defined architectures, controllable pore sizes, excellent reproducibility, higher pore interconnectivities and improved mechanical properties can be produced accurately and rapidly. This study describes the morphological and mechanical characterisations of porous Ultra-High Molecular Weight Polyethylene (UHMWPE) laser sintered parts to gain an insight into the correlation of process parameters and the morphological properties of these parts. Laser power was investigated to control the mechanical properties and porosity of the structures. The fabricated parts were characterised through porosity measurements, three point flexural test and scanning electron microscopy (SEM). X-ray micro-computed tomography (micro-CT) was considered to evaluate the mean internal porosity as well as the size and spatial distribution of pores inside the structure of the UHMWPE parts aiming at a better understanding of the three-dimensional internal morphology of UHMWPE laser-sintered parts. The porosity was then compared with the porosity measured using the helium gas pycnometer method. The results showed a high level of porosity in the UHMWPE laser-sintered parts with a range of 60-65% measured by micro-CT technique and helium gas pycnometer method respectively. There are no significant differences in the results obtained from both techniques and both results fit very well with each other. The results show that flexural strength decreases with an increase in porosity of the sintered parts. ; Mechanical Engineering

This work was supported by the European Union's Horizon 2020 research and innovation program under grant agreement No 875504 and the Spanish Government (CIU-19-RTI2018-099682-A-I00).