Influence of spherical indentor radius on the indentation-induced transformation behaviour of silicon

Nano-scratch, nanoindentation and fretting tests of 5–80nm ta-C films on Si(100)

“…Although the 170 nm ta-C film was harder (30 GPa) than the 80 nm ta-C, Haq et al reported a penetration depth at 10 mN of ~100 nm which could suggest that the radius of the tip was actually considerably less than the nominal 5 µm and/or it has developed some asperity damage at the tip. This would provide an explanation of why the critical loads in that study were observed at much smaller loads than in all of the reported tests on Si(100) with 4.2-5.0 µm indenters [7,8,15,32]. In the current work with a 4.6 µm end radius probe the on-load indentation depth was only ~75 nm for all the ta-C films and we did not see any critical loads until ~44 mN.…”

Effect of indentation unloading conditions on phase transformation induced events in silicon

“…2,4,5 Furthermore, the influence of a size effect for this phenomena within the microscale has been shown to not exist. 6 These events have also been seen to occur multiple times in unloading curves during cyclic loading conditions. 7 It was suggested that the pop-in event for spherical indenters is the result of a phase change from cubicdiamond Si-I to metallic ␤-tin Si-II, 2,8 which is known to occur between 11.3 and 12 GPa under hydrostatic loading in high-pressure cells.…”

IR investigation of density changes of silica glass and soda-lime silicate glass caused by microhardness indentation

“…For example, permanent deformation such as densification and plastic flow are observed during the indentation [1][2][3][4][5]. Crystallization and other phase transformation can also occur in many materials such as amorphous Si [6,7] and Ge [8,9]. At the same time, water can diffuse into oxide specimens at room temperature and cause indentation creep [10].…”