DISSOLUTION OF IRON IN THIN-LAYERS OF FE-B AND NI-B MELTS

The effect of temperature (1200 and 1250 degrees C) and sintering time (5 and 30 min) on the dissolution of armco iron in 200-500 mu m thick layers of Fe-B melt (5 and 10 wt.% B) is studied. Even after 5 min of heat treatment the composition of the melt corresponds to that of liq uidus in the Fe-B system phase diagram indicating definitively that sa turation concentration was reached in the melt. The concentration part ition of iron and nickel in the Ni-B (coat) - Fe (backing) transition zone is studied. The transition zone is found to be the result of two processes: diffusion of melt components into the solid backing and pre cipitation of a solid solution from the melt on the backing.