Abstract
Recently, laser additive manufacturing (AM) techniques have emerged as a promising alternative for the synthesis of bulk metallic glasses (BMGs) with massively increased freedom in part size and geometry, thus extending their economic applicability of this material class. Nevertheless, porosity, compositional inhomogeneity, and crystallization display themselves to be the emerging challenges for this processing route. The impact of these “defects” on the surface reactivity and susceptibility to corrosion was seldom investigated but is critical for the further development of 3D-printed BMGs. This work compares the surface reactivity of cast and additively manufactured (via laser powder bed fusion—LPBF) Cu47Ti33Zr11Ni6Sn2Si1 metallic glass after 21 days of immersion in a corrosive HCl solution. The cast material presents lower oxygen content, homogeneous chemical distribution of the main elements, and the surface remains unaffected after the corrosion experimentation based on vertical scanning interferometry (VSI) investigation. On the contrary, the LPBF material presents a considerably higher reactivity seen through crack propagations on the surface. It exhibits higher oxygen content, heterogeneous chemical distribution, and presence of defects (porosity and cracks) generated during the manufacturing process.
Highlights
Since the first synthesis in the 1960s, metallic glasses have been extensively investigated, especially in terms of mechanical properties
During the LPBF process, excessively large melt pools were observed in several specimens, resulting in disturbed heat flow or termination of the process
The result from this study showed an oxygen level of 1800 ± 20 ppm in the feedstock powder (20–90 μm) and 3677 ± 458 ppm in the LPBF sample, which was almost six times higher than in the cast sample
Summary
Since the first synthesis in the 1960s, metallic glasses have been extensively investigated, especially in terms of mechanical properties. The combination of high strength, superior hardness, large elastic strain limit, and improved wear and corrosion resistance make them promising candidates for a wide variety of engineering applications [1]. These properties are commonly attributed to the amorphous state, associated with the absence of grain boundaries, segregates, and microstructural defects. Alloys with one early and one late transition element, e.g., Cu-Ti-based, have a great difference in electrochemical potentials of the constituents This can lead to oxidation and partitioning effects, which in turn promotes crystallization due to the thermodynamical destabilization of the amorphous phase [4]. The atomic mobility can be reduced when small amounts of large-size elements are added [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
