Abstract
The microstructure of laser beam weld-metal of an yttrium doped directionally solidified alloy IC 6A, with chemical composition Ni-16Al-8.5Mo-0.12B-0.05C-0.03Y (at.%) was studied. The dendritic microsegregation observed within the fusion zone indicated that dendrite cores were slightly depleted in molybdenum and aluminum and the interdendritic regions were also considerably enriched in yttrium. Severe cracking in the weld-metal was observed and was found to be closely associated with interdendritic eutectic-type microconstituents identified as consisting of gama, gamma prime and Ni-Mo phases. An yttrium-rich phase (Ni3Y) was observed in some interdendritic regions containing the eutectic gamma, gamma prime and Ni-
Mo products. Their formation was discussed in relation to plausible microsegregation induced alteration of primary solidification path during
cooling from welding temperatures.
Mo products. Their formation was discussed in relation to plausible microsegregation induced alteration of primary solidification path during
cooling from welding temperatures.
| Original language | English |
|---|---|
| Pages (from-to) | 1504-1510 |
| Number of pages | 7 |
| Journal | Intermetallics |
| Volume | 15 |
| Publication status | Published - 2007 |