Nano-mechanical characterization of SLM-fabricated Ti6Al4V alloy: etching and precision

Abstract

In this research, we are reporting that the nanoindentation results vary between etched and unetched SLM-fabricated titanium alloy (Ti6Al4V) in spite of the same microhardness values. The dimensionless roughness parameter α, as a metric for the sensitivity of nano-hardness values on the surface roughness, is used to highlight whether etching plays any role. Although the value of α for both samples is below the recommended maximum value, the effect of etching is still significant. The hypothesis for a 19% increase in nano-hardness of etched samples is also discussed in this paper. Furthermore, the maximum proposed value of α (α < 0.05) appeared to be invalid for SLM-fabricated titanium and a lower value of α may need to be proposed as a critical value.