TENSILE PROPERTIES AND MICROSTRUCTURES OF NEUTRON-IRRADIATED V-TI-CR-SI TYPE ALLOYS

The alloy V-5Ti-5Cr-1Si-Al,Y has been investigated for fusion applications and demonstrates a good combination of its superior properties, such as (1) oxidation resistance in the fabrication process or in an oxygen atmosphere with high partial pressure, (2) bonding with ceramics for potential composite structure, (3) mechanical properties at a wide range of temperatures and (4) swelling behavior after irradiation. In the present study, tensile properties of the V-5Ti-5Cr-1Si-Al,Y alloy after neutron irradiation to high fluences were investigated and compared to other vanadium alloys. Specimens were tested using MATRON (monbusho automated tensile machine), which was installed in a multipurpose hot cell at Battelle Pacific Northwest Laboratory as pare of a joint Japan/US collaborative program for fusion materials research. The total elongation of V-5Ti-5Cr-1Si-Al,Y alloy tested at temperatures from ambient temperature to 600 degrees C after irradiation at 406 degrees C to 41dpa was 10 to 15%. Dense precipitation of Ti5Si3 was the typical microstructure of the alloy after neutron irradiation, which kept the alloy swelling low. The precipitation should have a major role in the low swelling behavior of the alloy without degradation of ductility.