Nanoindentation and Microscratch Studies of Nanostructured Titanium Diboride Coatings: Effect of Substrate Rotation

Abstract

Titanium diboride (TiB2) based nanostructured coatings up to 2.65 μm thick were deposited onhigh-speed steel by using magnetron sputtering technique. In order to achieve an extra hard andtough coating, effects of substrate rotation during deposition were thoroughly studied. X-raydiffraction (XRD) and field emission scanning electron microscopy (FESEM) were used to examine thephase and structure, respectively. Nanoindentation and microscratch test were conducted formechanical characterisation and coating adhesion examination, respectively. It was found that withoutsubstrate rotation, the adhesion, hardness and modulus have been improved tremendously due to theenhancement of coating thickness, the promotion of the (001) orientation, the decrease of averagegrain size, and the increase in coating density.

Keywords : Titanium Diboride / Magnetron Sputtering / Hardness / Adhesion / NanoindentationTest / Microscratch