Diffusion and Thermodynamics in the Ir-Nb System
The diffusion in indium-rich Ir-Nb alloys has been studied by single-phase interdiffusion experiments. The chemical diffusion coefficient has been measured for the primary fcc solid-solution and the L12 ordered compound Ir3Nb in the temperature range between 1650℃ and 1950℃, using Ir/Ir-8Nb and Ir-26Nb/Ir-28Nb diffusion couples, respectively (numbers indicate mol ％). While the chemical diffusion coefficient in the solid-solution phase is close to the tracer self-diffusion coefficient of pure iridium, the diffusion in the compound phase is extremely slow: the chemical diffusion coefficient is 1/40 to 1/50 of that in the solid solution. The low diffusion rate in the compound must be beneficial for high-temperature performance of refractory superalloys based on the Ir-Nb system.
NUMAKURA Hiroshi WATANABE Tatsuru YAMABE-MITARAI Yoko BANNAI Eisuke ABE Taichi CHEN Ying
Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University National Institute for Materials Science Department of Quantum Engineering and Systems Science, The University of Tokyo
国际会议
厦门
英文
666-675
2006-11-08（万方平台首次上网日期，不代表论文的发表时间）