This paper presents a critical analysis of the main factors of radiation damage limiting the possibility to use copper alloys in the ITER divertor and first wall structure. In copper alloys the most significant types of radiation damage in the proposed temperature-dose operation range are swelling, creep, and low-temperature radiation embrittlement. Low-temperature radiation embrittlement at T-irr < 150 degrees C presents considerable problems for dispersion strengthened (DS) and precipitation-hardened (PH) copper alloys, as their uniform elongation at T-test - T-irr - 100 degrees C drops to similar to 0.1% after irradiation doses of 0.01 to 0.1 dpa. At irradiation temperatures above 300 degrees C, pronounced softening occurs in PH copper alloys due to radiation-enhanced precipitate coarsening and dislocation recovery and recrystallization processes. The DS copper alloys are relatively resistant to radiation-enhanced softening up to temperatures of similar to 400 degrees C, The analysis of all available data indicates that copper alloys are suitable for structural applications in ITER components within a relatively narrow temperature range of 180 degrees C to 280 degrees C for PH alloys such as Cu-Cr-Zr and 180 degrees C to 350 degrees C for DS alloys such as oxide dispersion strengthened copper (e.g., GlidCop). Operation at lower temperatures is possible if uniform elongations < 1% can be tolerated in the design. Based on the available unirradiated and irradiated data, oxide dispersion strengthened copper (Cu-Al2O3) is considered to be the best candidate for high heat flux structural applications, followed by CuNiBe and CuCrZr.
|Journal||Journal of Nuclear Materials|
|Publication status||Published - 1996|
|Event||7th International Conference on Fusion Reactor Materials - Obninsk, Russian Federation|
Duration: 24 Sep 1995 → 28 Sep 1995
Conference number: 7
|Conference||7th International Conference on Fusion Reactor Materials|
|Period||24/09/1995 → 28/09/1995|