Effect of annealing on structure and temperature dependence of amorphous metal alloy microhardness

Temperature dependence of microhardness Hsub(ν) is studied for a series of amorphous metallic alloys (AMA) of the metal-metalloid type on the base of Fe, Co and Fe-Ni within the temperature range 77-293 K. When the temperature decreases from room temperature to 200 K Hsub(ν) changes but slightly, while further decrease of the temperature leads to essential growth. Annealing at 473 and 673 K slightly affects the structure and Hsub(ν)(T) of alllys. After annealing at 873 K the alloys pass to a crystalline state. It changes the Hsub(ν) value but the Hsub(ν)(T) dependence character remains unchanged. Such behaviour is explained by the possible covalent constituent in the interatomic AMA bond. It is shown that the Hsub(ν)/σsub(s) ratio (σ3-conventional yield point, determined from the data of tensile test) varies slightly depending on temperature and remain within 3.0-4.4