A. Baldan, COMBINED EFFECTS OF CARBIDE, CAVITATION AND THIN-SECTION SIZE ON THE CREEP-RUPTURE PROPERTIES OF A NICKEL-BASE SUPERALLOY, Zeitschrift fur Metallkunde, 85(6), 1994, pp. 400-407
The combined effects of thin-section size, carbide and cavitation disp
ersion on the creep rupture characteristics of the conventionally cast
MAR-M002 superalloy have been studied at 1173 K/300 MPa. It was shown
experimentally that the creep rupture life of the alloy is controlled
by the (a(c)/a(o))ID ratio, where a(c) is the cavity size, a(o) the c
arbide particle size and D the diameter of the gauge section of specim
en. Below a critical value (almost-equal-to 100 x 10(-6) mum-1) of thi
s ratio the rupture life extends rapidly, whereas above the critical v
alue of the ratio there is a slow increase in the rupture life. The ef
fect of the (a(c)/a(o)/D ratio on the rupture life has been described
using the existing theories which were developed for the prediction of
stress concentrations at grain boundary particles.