In-situ nanopillar compression analysis of prismatic and pyramidal slip strengths in Zr-Nb alloys

In-situ nanopillar compression tests were conducted to evaluate slip strengths of prismatic and pyramidal in Zr-Nb alloys. The resolved shear stress (RSS) for prismatic slip in Zr-2.5Nb is about five times that of Zr-1.0Nb at 298 K, and RSS for pyramidal slip of Zr-2.5Nb is about twice that of Zr-1.0Nb at 623 K, indicating that a higher density of β-Nb precipitates can appreciably enhance slip resistance. Moreover, RSS for prismatic slip in Zr-2.5Nb at 623 K is approximately one-tenth of that at 298 K, suggesting that the strengthening effect substantially reduces at reactor operating temperatures.