Ultrafine-grained nanocluster-strengthened alloys with unusually high creep strength

作者：Schneibel J H^*; Liu C T; Miller M K; Mills M J; Sarosi P; Heilmaier M; Sturm D

来源：Scripta Materialia, 2009, 61(8): 793-796.

DOI：10.1016/j.scriptamat.2009.06.034

• Mechanical alloying
• Oxide dispersion-strengthened (ODS) alloy
• Nanocluster (NC)
• Atom probe tomography
• Creep test

The microstructure and mechanical properties of ultrafine-grained ferritic alloys containing nanoclusters (NCs) are investigated. The NCs (diameter similar to 3 nm) as well as the grain size (similar to 200 nm) remain stable at 1000 degrees C. Substantial Hall-Petch strengthening occurs at room temperature. Surprisingly, the creep rate at 800 degrees C is up to a factor of 10(8) slower than that predicted for diffusional creep. Possible reasons are the high NC coverage as well as Cr and W enrichment at the grain boundaries, and inhibition of self-diffusion.

• 出版日期2009-10