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Thermomechanical Fatigue Behavior of a Silicon Carbide Fiber‐Reinforced Calcium Aluminosilicate Composite
Author(s) -
Butkus Lawrence M.,
Holmes John W.,
Nicholas Theodore
Publication year - 1993
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1993.tb04022.x
Subject(s) - materials science , composite material , silicon carbide , ultimate tensile strength , creep , calcium aluminosilicate , fatigue limit , isothermal process , residual stress , composite number , ceramic matrix composite , residual strength , stress (linguistics) , aluminosilicate , ceramic , modulus , fiber , biochemistry , chemistry , physics , linguistics , philosophy , thermodynamics , catalysis
Isothermal fatigue and in‐phase thermomechanical fatigue (TMF) tests were performed on a unidirectional, continuous‐fiber, Nicalon®‐reinforced calcium aluminosilicate glass‐ceramic composite ([O] 16, SiC/CAS‐II). Monotonic tensile tests were performed at 1100°C (2012°F) and 100 MPa/s (14.5 ksi/s) to determine the material's ultimate strength (σ ult ) and proportional limit (σ pl ). Isothermal fatigue tests at 1100°C employed two loading profiles, a triangular waveform with ramp times of 60 s and a similar profile with a superimposed 60‐s hold time at σ max . All fatigue tests used a σ max of 100 MPa (40% of σ pl ), R = 0.1. TMF loading profiles were identical to the isothermal loading profiles, but the temperature was cycled between 500° and 1100°C (932° and 2012°F). All fatigued specimens reached run‐out (1000 cycles) and were tested in tension at 1100°C immediately following the fatigue tests. Residual modulus, residual strength, cyclic stress‐strain modulus, and strain accumulation were all examined as possible damage indicators. Strain accumulation allowed for the greatest distinction to be made among the types of tests performed. Fiber and matrix stress analyses and creep data for this material suggest that matrix creep is the primary source of damage for the fatigue loading histories investigated.