Creep strengthening of Ni3(Al, Si) intermetallic alloy by ductile precipitates

Several methods were used to obtain the proper chemical composition and to determine the useful heat treatment to study the possible improvement of creep behaviour by fine precipitates of γ phase (disordered and ductile) in Ni3Al alloy (ordered γ′ phase), which is an inverted structure with respect to that of superalloys. present work, compression creep tests were performed on the Ni78Al11Si11 alloy (in at.%) at temperatures and stresses near that of the flow stress peak observed at about 550 °C. The stress exponent and activation energy of creep were determined. First observations of the microscopic creep behaviour were made after a low strain by transmission electron microscopy.