Compressive strengths of molybdenum alloy micro-pillars prepared using a new technique

Single-crystal micro-pillars of a molybdenum alloy were prepared by a new technique that involves chemically etching away the matrix of a directionally solidified NiAl–Mo eutectic. The square cross-section pillars had edge dimensions ranging from ∼360 to ∼1000 nm. When tested in compression with a nanoindentation system, the pillars all yielded, regardless of size, at a critical resolved shear stress of 4.3 GPa, or G/26, where G is the shear modulus. This shear yield strength is in the range expected for the theoretical strength, G/30 to G/10.