A FINING MECHANISM OF THE LASER SOLIDIFIED MICROSTRUCTURE FOR Fe-AND Ni-BASE ALLOYS
激光快速熔凝Fe基、Ni基合金的细化形态

Laser rapid solidification treatment on pure Fe,20 steel andNi-base alloy is performed by means of pulse laser.The results show thatsome epitaxially growing grains are formed in the melted zones of pure Fe andNi.The epitaxially growing grains and fine dendritic microstructures are formedin the 20 steel and Ni-base alloy.Meanwhile,a large amount of fined sub--grains appear in the melted zones of the metals and the alloys.The epitaxiallygrowing grains in laser melted zones are not fined,but the dendritic micros-tructures and sub-grains are fined greatly.