DIRECTIONALLY-SOLIDIFIED EUTECTIC TYPE ALLOYS WITH ALIGNED DELTA PHASE

摘要

1407871 Directionally solidified castings UNITED AIRCRAFT CORP 22 Jan 1973 [27 Jan 1972] 3127/73 Heading B3F A directionally solidified nickel-based alloy casting having an overall eutectic composition which is thermodynamically monovariant or multivariant consists of a lamellar phase dispersed in a matrix phase, the lamellae being in alignment with each other. The lamellar phase is Ni 3 Nb or Ni 3 Ta or Ni 3 (Nb.Ta) and the matrix phase is a nickel-based solid solution containing up to 35 wt. per cent Cr and/or up to 4 wt. per cent Al. The castings may be made by directional plane-front solidification at solidification rates of 2 to 10 cm./hr. Directional solidification with a cusped liquid/solid interface at higher solidification rates produces alloys with the aligned lamellar phase.