Original paper(Vol.46 No.9 pp.1107)

Capability of advanced three-dimensional fractographic technique, FRASTA

Fujihara Masaharu; Yoshimoto Kentaro; Kondo Yoshiyuki

Abstract:The fracture surface topography analysis (FRASTA) technique which reconstructs the fracture process from the three-dimensional topographs of conjugate fracture surfaces has been used to characterize fracture mechanisms and obtain detailed information about microprocesses.
In this study, the FRASTA technique was applied to four types of fracture surfaces: (1) brittle fracture of ceramics, Si sub 3N sub 4, (2) stress corrosion cracking (SCC) fracture of 12CrMo stainless steel, (3) fatigue fracture of cast iron, FC250, and (4) fatigue fracture of low alloy steel, SFVQ2A. The FRASTA results of these fracture surfaces were compared at each test condition after analysis to evaluate the FRASTA capability and its limitations.
From the results, it was found that FRASTA had capability to reconstruct the detailed fracture process and to detect condition changes such as stress or environment, but there were some difficulties in the estimation of crack growth rate or applied stress.

Key Words:fractography, brittle fracture, fatigue fracture, stress corrosion cracking, fracture process, condition change, crack growth rate, applied stress