The Mechanical Properties of a Ni-30Al-20Fe-0.05Zr Intermetallic Alloy in the Temperature Range 300-1200 KTensile tests were conducted on an extruded Ni-30(at. pct)Al-20Fe-0.05Zr intermetallic alloy in the temperature range 300-1200 K, and the microstructures were characterized by optical, scanning, and transmission electron microscopy. The alloy did not exhibit any room temperature ductility and failed by transgranular cleavage at a stress of about 710 MPa. This mode of fracture was observed at and below 873 K with the total ductility being less than 2.5 percent. However, the failure mode changed to dimpled fracture, triple point cracking, and rupture above 873 K. Scanning electron microscopy of the fracture surfaces revealed that transgranular cleavage failure had always originated at preexisting defects. In these cases, the fracture stress exhibited a good correlation with the defect size, in accordance with linear elastic fracture mechanics, where the critical stress intensity factor was estimated to be about 4 MPa sq rt m.
Document ID
19920048169
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Raj, S. V. (NASA Lewis Research Center Cleveland, OH, United States)
Noebe, R. D. (NASA Lewis Research Center Cleveland, OH, United States)
Locci, I. E. (NASA Lewis Research Center Cleveland, OH, United States)