Tribological and corrosion properties of Al–12Si produced by selective laser melting

Abstract

The effect of annealing on the tribological and corrosion properties of Al-12Si samples produced by selective laser melting (SLM) is evaluated via sliding and fretting wear tests and weight loss experiments and compared to the corresponding material processed by conventional casting. Sliding wear shows that the as-prepared SLM material has the least wear rate compared to the cast and heat-treated SLM samples with abrasive wear as the major wear mechanism along with oxidation. Similar trend has also been observed for the fretting wear experiments, where the as-prepared SLM sample displays the minimum wear loss. On the other hand, the acidic corrosion behavior of the as-prepared SLM material as well as of the cast samples is similar and the corrosion rate is accelerated by increasing the heat treatment temperature. This behavior is due to the microstructural changes induced by the heat treatment, where the continuous network of Si characterizing the as-prepared SLM sample transforms to isolated Si particles in the heat-treated SLM specimens. This shows that both the wear and corrosion behaviors are strongly associated with the change in microstructure of the SLM samples due to the heat-treatment process, where the size of the hard Si particles increases, and their density decreases with increasing annealing temperature.

Effect of Particle Size on Microstructure and Mechanical Properties of Al-Based Composite Reinforced with 10 Vol.% Mechanically Alloyed Mg-7.4%Al Particles

“…The wear tracks of the composites show the presence of typical wear features including wear scars, ploughing grooves, and delamination. The composites with (80-100 µm) particle size show shallow ploughing grooves along with the presence of some delamination cracks (Figure 4a), which are formed at the surface of the sample in contact with the counter disc due to high strain levels developed during the wear test [33][34][35]. The samples of 40-80 µm particles size (seen in Figure 4b) also show a similar nature of wear surface but ploughing groves are not clearly visible.…”

Processing of Al–12Si–TNM composites by selective laser melting and evaluation of compressive and wear properties

“…[5][6][7][8] This process is also believed to lower the production time of complex parts, to maximize material utilization, and is considered to be environmentally friendly. 9 Most of the SLM research is focused on the following alloys: (i) pure iron, stainless steel, and different tool steel grades in the directions of parameter optimization, structure optimization, and evaluation of mechanical properties [10][11][12][13] ; (ii) Al-based alloys, like Al-12Si and AlSi10Mg, mainly focused on parameter optimization and evaluation of various properties [14][15][16] (iii) Ti6Al4V (for high strength aerospace applications), pure titanium and beta titanium alloys (bulk and porous scaffolds for bio-medical applications) focusing on the parameter optimization and evaluation of related bio-medical, corrosion and mechanical properties [17][18][19][20] ; (iv) Ni-based alloys like nitinol, inconels, and waspaloys (for high temperature properties and shape memory effects) mainly focused on parameter optimization and high temperature properties [21][22][23][24] and (v) Co-based alloys (CoCrMo as dental implants) focused on the microstructure and biomedical properties. 25,26 Altogether, the majority of the research shows that parts produced by SLM have improved properties compared to parts produced by conventional casting/powder metallurgy techniques.…”

“…25,26 Altogether, the majority of the research shows that parts produced by SLM have improved properties compared to parts produced by conventional casting/powder metallurgy techniques. 14,15 Several attempts were made to further improve the properties (mechanical, tribological, and bio-medical) of SLM produced parts by adding reinforcing particles to the metal matrix. For example, Song et al added hard SiC to pure Fe-powder to improve the mechanical properties of the iron matrix produced by SLM.…”

Tensile Properties of Al-12Si Fabricated via Selective Laser Melting (SLM) at Different Temperatures

“…It has also been observed for as-prepared SLM-fabricated Al-12Si samples that the Si concentration is higher along the hatch overlaps [18]. A cellular microstructure is observed in the core of the sample, where the cell boundaries are enriched in Si compared to the cell interior [17,18]. On the other hand, the hatch overlaps show an elongated morphology.…”

“…The Si peaks are not predominant but rather weak in intensity. This suggests a reduced amount of free residual Si (~1 wt %) in the as-prepared material, which is due to the extended solid solubility of Si in Al [17,18]. The lattice parameter of the Al phase is 0.40508 ± 0.00002 nm with crystallite sizes (calculated from the XRD data) of 118 ± 2 nm and 8 ± 1 nm for Al and Si, respectively.…”