PROPERTIES OF DISPERSION-STRENGTHENED CHROMIUM - 4-VOLUME-PERCENT-THORIA ALLOYS PRODUCED BY BALL MILLING IN HYDROGEN IODIDE

摘要

The effects of processing variables on the tensile properties and ductile-to-brittle transition temperature (DBTT) of Cr + 4 vol. % ThO2 alloys and of pure Cr produced by ball milling in hydrogen iodide were investigated. Hot rolled Cr + ThO2 was stronger than either hot pressed Cr + ThO2 or pure Cr at temperatures up to 1537° C. Hot pressed Cr + ThO2 had a DBTT of 501° C as compared with -8° to 24° C for the hot rolled Cr + ThO2 and with 139° C for pure Cr. It is postulated that the dispersoid in the hot rolled alloys lowers the DBTT by inhibiting recovery and recrystallization of the strained structure.