Thermo-mechanical fatigue of a SiCw/6061A1 composite

In-phase (IP) and out-of-phase (OP) thermo-mechanical fatigue (TMF) experim ents were undertaken on 6061 aluminum alloy reinforced with 15% volume frac tion whiskers. Both TMF tests were conducted under mechanical strain range control with temperature cycling between 150 similar to 300 degrees C. The mechanical behavior and fatigue resistance of both TMF fatigue was investig ated and discussed. The result shows that the two kinds of TMF cycling exhi bited continuous cyclic softening, out-of-phase TMF loading gave rise to te nsile mean stress, whereas in-phase TMF cycling led to compressive mean str ess. It is also illustrated that at small strain range, the in-phase TMF li fe was longer than that of the out-of-phase TMF: on the contrary, out-of-ph ase TMF showed longer life at large strain range. This is tentatively expla ined by the various damage mechanisms with the help of SEM?, which were pre dominantly operative under different strain ranges and different phasing co nditions.