Abstract: The present invention describes the process for enriching the surface of ferromagnetic particles and coating ferromagnetic particles. More specifically the present invention describes the obtainment of materials developed by processes of: surface enrichment, surface oxidation, particle coating via dry powder mixing by tumbling, via reactions with boron compounds, via liquid glassy suspension and non-metallic compounds, and the possibility of using one or more of the techniques described concomitantly. The present invention is in the field of Mechanical Engineering, Electrical Engineering, Chemical Engineering and Materials Engineering.

Abstract: A process for the synthesis of nanostructured metallic hollow spherical particles, in which the metal is deposited onto sacrificial masks formed in a polymeric colloidal solution by the electroless autocatalytic deposition method. Deposition releases only gaseous products (N2 and H2) during the oxidation thereof, which evolve without leaving contaminants in the deposit. The particulate material includes nanostructured metallic hollow spherical particles with average diameter ranging from 100 nm to 5 ?m and low density with respect to the massic metal. A process for compacting and sintering a green test specimen are also described.

Abstract: A process for the synthesis of nanostructured metallic hollow spherical particles, in which the metal is deposited onto sacrificial masks formed in a polymeric colloidal solution by the electroless autocatalytic deposition method. Deposition releases only gaseous products (N2 and H2) during the oxidation thereof, which evolve without leaving contaminants in the deposit. The particulate material includes nanostructured metallic hollow spherical particles with average diameter ranging from 100 nm to 5 ?m and low density with respect to the massic metal. A process for compacting and sintering a green test specimen are also described.

Abstract: The process basically comprises: dissolving a lamellar disulphide, as a source of the solid lubricant, in an aqueous solvent, forming a first aqueous solution; dissolving a reducing agent, as hydroxylamine, sodium hypophosphite or sodium borohydride, in an aqueous solvent, forming a second aqueous solution; mixing the first and second aqueous solutions, forming a third aqueous solution; neutralizing the pH of the third aqueous solution; dissolving a sulphur source, in an aqueous solvent, forming a fourth aqueous solution; mixing the third and fourth aqueous solutions, forming a fifth aqueous solution, which is contained and heated in an autoclave; cooling the fifth aqueous solution to the room temperature; and removing, from the autoclave, the nanoparticles in powder form.

Abstract: The process basically comprises: dissolving a lamellar disulphide, as a source of the solid lubricant, in an aqueous solvent, forming a first aqueous solution; dissolving a reducing agent, as hydroxylamine, sodium hypophosphite or sodium borohydride, in an aqueous solvent, forming a second aqueous solution; mixing the first and second aqueous solutions, forming a third aqueous solution; neutralizing the pH of the third aqueous solution; dissolving a sulphur source, in an aqueous solvent, forming a fourth aqueous solution; mixing the third and fourth aqueous solutions, forming a fifth aqueous solution, which is contained and heated in an autoclave; cooling the fifth aqueous solution to the room temperature; and removing, from the autoclave, the nanoparticles in powder form.