Patent ID: 6778916
Filing Date: 2004-08-17
Classification: G01N

Abstract:
An automated indentation system for performing a compression test by loading a compressive indentation load (P), thereby calculating an elastic modulus (E), yield strength (&sgr;0) and a hardening exponent (n) from measured indentation depth (ht), indentation load (P) and unloading slope (S), comprises:a step-motor control system (1) having a cylindrical linear actuator with a ball screw (14) and backlash nut (16) for suppressing backlash, a flexible coupling (13) being connected to said ball screw (14) and a step-motor (12) for constraining rotation and high repeatability, a measurement instrumentation (2) having a load cell (15), laser displacement sensor (17) for measuring the indentation depth, and an integrated ball indenter (18), a data acquisition system (3) having an signal amplifier for amplifying and filtering signals received from said load cell (15) and laser displacement sensor (17), and a control box (4) being pre-stored computer programming algorisms for adjusting and controlling moving speed and direction of said step-motor (12), performing calculations and plotting graphs of load-depth curves, strain-stress curves based on said amplified signal data, and said control box (4) for storing and retrieving measured signal data, material properties and produced data.