THE GLASS-FORMING ABILITY IMPROVEMENT OF Co₄₁Fe₇Cr₁₅Mo₁₄C₁₅B₆ ALLOY DURING DILUTION WITH RARE EARTH METALS

Abstract

Eutectic alloys, due to their low melting point, are promising materials for the production of metal glasses. Unlike crystalline alloys, amorphous alloys have no long-range order, which leads to an increase in hardness, mechanical strength, corrosion resistance and magnetic permeability. The main criterion for the application of amorphous materials in practice, under which the formation of a single-phase metallic glass during quenching, is the critical diameter. Therefore, an urgent task in this area of research is to increase the critical diameter of current amorphous alloys. One of the methods of improving the glass-forming ability of alloys is their dilution with more refractory metals. In this paper, we present amorphous metallic glasses of (Co41Fe7Cr15Mo14C15B6)100 – xRx alloys with dilution with rare earth metals (R = Gd, Ho, La, Nd, Y, Yb; x = 0; 2). The critical diameter, phase and elemental composition of the alloys depending on the quenching rate were determined by X-ray diffraction and scanning electron microscopy. It is shown that the addition of 2 at. % Gd, Ho and Y significantly increases the glass-forming ability of the Co–Fe–Cr–Mo–C–B alloy. By spinning method, when quenched on an aluminum disk rotating at a linear speed of 11.5 m/s, tapes with a thickness of 19 to 73 microns were obtained. Rare inclusions with a high content of rare earth elements up to 35 at % were found on the surface of the tapes, which can act as crystallization centers.