Apparatus and system for measuring mechanical properties of materials using depth sensing indentation

摘要

Apparatus for use in determining a property of a sample material tested by a depth sensing indentation system, comprises a memory storing data points on a load-displacement curve for a test of the sample generated by the depth-sensing indentation system, the data including an unloading curve of the measured displacement, ℎ, of the probe of the indentation system as the previously applied indentation load, P, thereon is released; a full elastic point, FEP, determination module configured to determine, based on the unloading curve data, a point on the unloading curve having the highest load at which the measured acceleration of the indenter displacement, optionally using d2h/dP2 as dP/dt as constant, becomes a constant indicating that the indenter and sample thereafter move together at the same speed, said point taken to be the full elastic point, FEP, at which any delayed elasticity in the sample in response to the indentation ceases; and a material property determination module configured to determine, based on the unloading curve data at the FEP, one or more material properties of the sample.