EFFECT OF ANNEALING ON THE STRUCTURE AND PROPERTIES OF AMORPHOUS ALUMINUM-BASE ALLOYS

The thermal stability of amorphous Al-Ni-Y and Al-Ni-Si alloys produce d by melt spinning was assessed by studying the effect of isothermal a nd isochronous annealing on their structure and some of the properties . Al-Ni-Y alloys are more prone to amorphitization, exhibit an endorth ermal effect at 240 degrees C (on the DTA curves) and remain amorphous on heating up to 200 degrees C. Their microhardness in the amorphous state is 385 kg/mm(2), increasing to 490 kg/mm(2) after annealing at 3 00 degrees C. Annealing at 100 and 150 degrees C has little effect on the microhardness and plasticity. The brittleness threshold of these a lloys can be assumed as 150%.