Universal Scaled Strength Behaviour for Micropillars and Nanoporous Materials

The strength of submicron FCC structure metal columns, σ, fabricated by FIB machining or electrodeposition, shows a strong correlation with specimen diameter, d, with σ/μ = A(d/b) −0.63, where A is a constant, μ is the single crystal shear modulus resolved onto the slip system and b is the Burgers' vector. The strength of BCC structure metals does not show such a well defined correlation with size across different metals but the data occupies the same region of parameter space as with the FCC metals. Nanoporous gold specimens show a similar size-correlated behaviour but with an exponent of −0.5. This may indicate different mechanisms operating in each case.