No abstract

No abstract

No 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.

Martensite transformation was studied in 16 steel compositions with various C, Mn, Si, Al, and Cr contents. Different annealing treatments were performed on the elaborated steels to obtain different prior austenite grain sizes (PAGSs) and M s temperatures. This permitted the concomitant evolution of M s temperature as a function of chemical composition and PAGS. The experimentally built database allowed the decorrelation of the effects of chemical composition and PAGS, and a new empirical equation to predict M s temperature was proposed. The obtained experimental results and equation are discussed, and some future improvements are proposed.

No abstract

No abstract

No abstract