EFFECT OF SPECIMEN SURFACE PREPARATION ON ROOM-TEMPERATURE TENSILE DUCTILITY OF AN FE-CONTAINING NIAL SINGLE-CRYSTAL ALLOY

In a study of scatter in the room temperature tensile ductility of a F e-containing NiAl alloy, surface preparation of machined tensile speci mens has been found to play a very critical role in affecting the meas ured ductility. Room temperature tensile plastic elongations varied fr om about 0.4% for the as-ground specimens to about 8% for the electrop olished specimens when the grinding marks were completely removed. The surface effect was related to high defect sensitivity of NiAl due to low ductility and low fracture toughness. Similar behavior has been re ported in other intermetallic alloys. Copyright (C) 1996.