29th Symposium on Fusion Technology (SOFT 2016)

P2.182 Thermal conductivity and diffusivity of Cu-Y alloys produced by different powder metallurgy routes

6 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 182

Poster I. Materials Technology P2 Poster session

Speaker

Gabriel Carro (Physics)

Description

Copper-based materials are considered the most promising candidates for water-cooled components of the heat sink systems of future fusion reactors. Although pure copper is the material with the higher thermal conductivity, the detriment of its mechanical strength on increasing temperature restricts its use at high temperature. In the last years, ODS Cu-Y2O3 and Cu-Y alloys have been produced following PM (powder metallurgy) routes and subsequent consolidation by HIP (hot isostatic pressing). The different approaches include the milling of pure copper with nano-sized particles of Y2O3 or pure Y powders, and the utilization of prealloyed Cu-0.8%Y powders obtained from vacuum induction melting and atomization. Microstructural studies showed that Y and/or Y2O3 particles are formed and are homogeneously distributed in the copper matrix. Tensile tests performed in the temperature range 293-773 K indicated that the presence of these particles give place to a reinforcement of the matrix copper. The effect of the equal channel angular pressing (ECAP) thermo-mechanical treatment in the microstructure and mechanical properties was also evaluated. In this work, the thermal properties in the temperature range 300 - 773 K of ECAPed and non-ECAPed Cu-1%Y2O3 and Cu-0.8%Y alloys will be presented. The thermal expansion has been measured by using a dilatometer. The thermal diffusivity and specific heat have been determined by the Laser Flash technique. From these measurements, the thermal conductivity of the alloys has been estimated. The results indicate that the ECAP process enhances the thermal conductivity of the alloys.