High temperature fatigue characteristics of P/M and hot-forged W-Re and TZM for X-ray target of CT scanner

Publication date: 5 January 2018
Source:Materials & Design, Volume 137
Author(s): Mohd Azhar Harimon, Yukio Miyashita, Yuichi Otsuka, Yoshiharu Mutoh, Shinichi Yamamoto
The fatigue strengths at 1000°C of layered W-Re/TZM, bulk W-Re and bulk TZM for x-ray target materials were successfully evaluated under load-controlled four-point bending by introducing a fatigue failure criterion as two-times increase of initial compliance. The obtained fatigue strengths at 1000°C for layered W-Re/TZM and bulk W-Re were similar and 280MPa and 290MPa at 10⁶cycles, respectively, while that of bulk TZM was 200MPa. During fatigue loading at 1000°C, dominant fatigue damage would be multiple intergranular crack nucleation and propagation, which would induce the increase of compliance. The reasonability of the fatigue failure criterion was confirmed by the fatigue process observations and the results of room temperature fatigue tests of the specimens tested at 1000°C up to the cycles corresponding to the fatigue failure criterion.

Graphical abstract

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