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Ferromanganese nodules represent an industrially untapped source of valuable metals (Mn, Cu, Ni, Ti, Co) but are still just the object of scientific research. In comparison with already utilized rocks, deep-sea deposits are too hard to reach for their full-scale mining to be profitable. Despite of this, current marine engineering allows us to conduct complete exploration and obtain mineral samples. We can already now develop low-cost methods for subsequent processing in anticipation of improved and safer future mining technology. But in what form would be the final product the most applicable? In our study, we reduced the pyro metallurgical pretreatment of raw nodules to two simple steps: roasting and aluminothermic reduction. Then we added a product, manganese-based alloy, to pure aluminum as a new alloying additive. As a reference for experimental alloys, commercial cast AlMn10 master alloy was chosen. The tested samples were prepared using two advanced operations of powder metallurgy: melt-spinning and spark plasma sintering (SPS). Microstructure was described in detail, tribological and selected mechanical properties were measured, and a comparative analysis was conducted. New additive gradually improved properties of alloys to a level close to 3xxx industrial alloys with its increasing percentage in pure aluminum. Measured values did not surpass the referent AlMn10, but there was not recorded any adverse impact associated with the origin of alloying mixture. • New aluminum alloys with the natural additive – reduced deep-sea nodules – modified by rapid solidification. • Extremely fine-grained microstructure with the content of supersaturated matrix regions. • Improved mechanical and tribological properties comparable to commercial alloys of 3xxx group. • Uncommonly high plasticity. [ABSTRACT FROM AUTHOR]

Due to the lack of mineral resources, unconventional raw materials have to be considered. In this work, the use of reduced deep-sea nodules from Clarion-Clippertion Fracture Zone of Pacific Ocean was tested as the natural mixture of alloying elements for aluminum alloys. The nodules were reduced by aluminothermic process without the extraction of individual elements. As the technology for the manufacture of the alloys, the powder metallurgy comprising mechanical alloying and spark plasma sintering was applied. The produced Al-Mn based alloys are characterized by uncommon spherical morphology of Al-Mn intermetallics, which leads to a significant ductility even in the case of high total amount of additives (up to 20 wt%). The wear resistance of the alloys strongly increases with growing amount of the reduced deep-sea nodules. • New aluminum alloys with reduced deep-sea nodules prepared by powder metallurgy. • Unique rounded morphology of intermetallics was obtained. • Improved strength compared with common Al-Mn alloys. • Reduced deep sea nodules improve tribological properties of aluminum. [ABSTRACT FROM AUTHOR]

Abstract: In this work, Ti–Al–Si alloys were prepared by reactive sintering. The contents of silicon and aluminium ranged between 0–30wt.% and 0–36wt.%, respectively. Powders of titanium, aluminum, silicon and AlSi30 master alloy prepared by mechanical machining and/or milling were used for sintering. Powders were blended and pressed at room temperature. Sintering was carried out at 900°C for 30min. It was found that it is possible to produce compact materials with the structure corresponding to the as-cast materials when silicon is in the range of 15–20wt.% and aluminium content between 8 and 30wt.%. It was shown that these materials contain two phases—Ti5Si3 and TiAl. The central porosity can be reduced by induction heating. [Copyright &y& Elsevier]

Abstract: Positron annihilation spectroscopy was employed for the microstructure characterization of rapidly solidified Al–3wt.% Cr–3wt.% Fe–0.8wt.% Ce alloy prepared by melt spinning. Results of the positron annihilation study are analyzed within the diffusion trapping model and compared with results of X-ray diffraction, transmission electron microscopy and microhardness measurements. A good consistency among all experimental techniques was obtained. The rapidly solidified alloy exhibits ultra fine grained structure, consisting of cells separated by dislocation walls. Annealed samples showed no significant changes in structure up to 400°C which proves good thermal stability of ultra fine grained structure. Exposure of the sample to temperature of 500°C caused significant changes in the material. [ABSTRACT FROM AUTHOR]