在电子探针测量的基础上,根据扩散理论和Ir-Re相图数据,建立了一个全新的Ir/Re两相扩散模型。计算得到在1200℃~2000℃时Ir基固溶体中的互扩散系数为:D=1.17×10^-6exp(-1.80eV/kT)(cm^2/s),Re基固溶体中的互扩散系数为:D=1.36×10^-4exp(-1.21eV/kT)(cm^2/s).确定喷管中Ir/Re为品界扩散。
Interdiffusion problem of iridium/rhenium was studied during preparation of iridium/rhenium thruster. The diffusion model and solution of iridium/rhenium was given based on measurement of EPMA, diffusion theory and phase diagram. Interdiffusion coefficient in iridium solid solution and in rhenium solid solution is: D=1. 17× 10^-6 exp(-1.80 eV/kT)(cm^2/s) and D=1.36× 10^-8exp(-1.21 eV/kT) (cm^2/s), respectively, between 1200℃~2000℃. Iridium/rhenium diffusion is grain boundary diffusion in the thruster.