Determination of Gold Surface Mechanical Behavior in Electro-Thermo-Mechanical Coupled Service Using Atomic Force Microscopy

In this paper, gold (Au) surface mechanical behaviors in electro-thermo-mechanical coupled service are studied using atomic force microscopy. The experimental results indicate that some pile-ups of the metal, caused by indentation, are formed whether or not an external electric field is applied during indentation. Scanned topographical images reveal a bright area around the indentation hole, indicating the area where the material had been pushed out. It was determined that when a DC external field is applied to a sample, the hardness value of the tested sample presents an increase trend with the increment of electric current, but a decrease trend for the residue area and the elastic modulus.