Andre Mussatto's research while affiliated with Dublin City University and other places

... Bioactive bone substitutes, which could be gradually resorbed in vivo and replaced by new bone tissue, thus realizing the self-repair of bone defects, have received increased attention in recent years [1][2][3]. When load-bearing bones or large segmental bones are targeted, it remains a scientific challenge for the scaffolds to maintain both the required interconnected three-dimensional structure and comprehensive mechanical properties (strength and toughness). ...

... The phases presented in the samples were determined using a triple-axis Jordan Valley Bede D1 high resolution x-ray diffraction system with a copper (λ = 1.5405 Å) radiation source operated at 45 kV and 40 mA [41]. Structural changes also were examined by Fourier transform infrared spectroscopy using a Perkin Elmer Spectrum Two spectrometer. ...

... Structural changes also were examined by Fourier transform infrared spectroscopy using a Perkin Elmer Spectrum Two spectrometer. The three-point bending and compression tests were performed using a Zwick Z050 (Zwick/Roell GmbH, Germany) fitted with Zwick TestXpert software and a 50 kN load cell [42]. The support span length of the three-point outer jaws was 48 mm. ...

... Improved resource utilization and unparalleled designing are the most prominent benefits of this technique, however these come along with anomalies within the final product [16]. Post-processing techniques are often utilized to improve the final part properties [17][18][19]. For laser-based material processing, Design of Experiment (DoE) based Response Surface Methodology (RSM) is commonly used for process development and determination of processing parameter values which produce desired properties to avoid anomalies [20][21][22]. ...

... The overlap percentage is controlled by a linear motion from the CNC control system and rotational motion from the samples, which contributes to improving the 'waving effect' between the build layers and successive laser tracks in both L-PBF and laser polishing processes, respectively. Muhannad et al. [51] investigated the surface polishing of cylindrical AMed Ti6Al4V with different overlaps (25,50, and 75%). The lower overlap percentage (see Fig. 4c) resulted in improved surface roughness (from 10.9 to 5.1 μm). ...

... Numerous experimental techniques have been used to characterise the AM spreading process and the resulting powder layers. Examples include microscopy methods that image the top surface particles and map the surface topography to calculate uniformity and roughness [14,15], and contact scanning apparatuses attached to the recoater to capture the surface height field during spreading [16][17][18]. Simple sample-and-weigh techniques are often used to measure the global packing density of the powder after spreading [19,20]. ...

... The characteristics of the powders play a fundamental role in the quality of the final product. It has been shown that consistency and sphericity are important characteristics for having uniformity in the powder bed [19]. Although it is necessary to fill the entire build volume to the height of the tallest object to be produced, much of the dust is not directly exposed by the laser beam to produce the part itself. ...

... The authors claimed that wide particle size distribution (2-70 μm) gives a better tap/netshape density as well as a lower surface roughness whereas a narrow distribution (15-70 μm) results in a better flowability and a higher ultimate tensile strength [32]. A decrease in average particle size has been also reported to produce lower surface roughness [33], whereas an average particle size value above the range 28-38 μm leads to an increase in porosity [34]. An adaptation of the manufacturing parameters to particle size distribution has been also reported to ensure high-density samples [35][36][37]. ...

... During the past several decades, many in-situ methods [21][22][23][24][25][26], such as exothermic dispersion (XD), self-propagating high temperature synthesis (SHS), and reactive gas infiltration have been developed to fabricate AMCs with ultrafine reinforcing phases, which are synthesized in-situ inside the Al matrix by chemical reactions between elements or between elements and compounds. The main attractive advantages of in-situ AMCs include fine and thermodynamically stable reinforcements, and strong reinforcement-matrix interfaces [27], thus leading to better mechanical properties of AMCs. However, in-situ synthesized products usually have high porosity, and secondary processing is necessary to obtain densified AMCs. ...

... 8,9 When a spatter lands on the powder bed and is not being built in the part, it can still cause a decreasing powder quality and a limited recyclability. 10,11 Obeidi et al. unveiled that spatters can form non-spherical agglomerates in the powder bed, which increase the degradation of the powder bed. 11 When the powder is reused, these non-spherical spatters, which remained after sieving, can deteriorate the recoating process and finally lead to part defects. ...