Z. F. Wan
,
X.D. Hui
,
G.Q. Yuan
,
Y. S. Yang and X.C Chen (Shandong University of Technology
,
Jinan 250061
,
China)(Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China)(Institute of Physics
,
The Chinese Academy of Sciences
,
Beijing 100080
,
China)
金属学报(英文版)
The initiation and propagation of the short fatigue crack in a 10vol% titanium carbide particulate reichreed cast Fe-26Cr-14Ni mathe coopsite at 1023K were investigated.It is shown that the titanium carbide particulate may hinder the crack propagation and fatigue fracture of the composite. The relationships between fatigue crack propagation rate and stress intensity factor are da/dN=4.2×10-c(△K)4 for the matrix alloy and da/dN=1.4×10-19(△K)c for the composite. The fatigue thresholds of the composite and mathe alloy are 78 and 3.2MPa.m1/2, respectively. Microcracks initiate at the intedece between titanium carbide particulate and austenite and then propagate in carkide particles. The fracture sudece of the composite shows a distinct transition from wavy and serated cleavage near the threshold regime to striation-type splitting in the stable fatigue crack propagation stage and to a veined morphology characteristic in unstable rapid region.
关键词:
fatigue crack
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