The effect of aluminium on mechanical properties and thermal stability of (Fe, Ni) -Al-P ternary amorphous alloys

Abstract

Amorphous phase formation with good ductility has been found in Fe-Al-P and Ni-Al-P ternary systems by using a melt-spinning technique. The aluminium content of these amorphous alloys is in the range 0 to 18 at% for the Fe-Al-P system and 0 to 6 at% for the Ni-Al-P system. Crystallization temperature and Vickers hardness increase with increasing aluminium and phosphorus content and maximum values are attained at 721 K and 640 diamond pyramid number (DPN). Their fracture strengths are about 2000 MPa. The effectiveness of aluminium on the increase in crystallization temperature is very great, being almost the same as that of silicon and the refractory metals such as vanadium, niobium, molybdenum and tungsten, but its effectiveness on the increase in hardness is not so great. From the previous data on the effect of aluminium on the activity coefficient of phosphorus in molten iron, it is inferred that the effectiveness of aluminium is due to the attractive interaction between aluminum and iron or nickel which is greater than that between aluminium and phosphorus.