TEM INVESTIGATION OF THE PLASTIC ZONE, DISLOCATION ROSETTES AND CRACKS AROUND VICKERS INDENTATIONS IN SILICON. by Samuels, J, Pirouz, P, Roberts, S, Warren, P, Hirsch, P

The use of closely spaced vickers indentations to model erosion of polycrystalline α-Al2O3 by Franco, A, Roberts, S

Indentation fracture toughness and surface flaw analysis of sintered alumina/SiC nanocomposites by Anya, C, Roberts, S

“…The fracture toughness (K1c) of pressureless-sintered monolithic α-alumina and its composites with 5, 10 and 15 vol% SiC nano-sized particles was investigated using Vickers indentation and a new Hertzian (ball) indentation technique. …”

Substrate and elastic recovery effects in hardness measurement of CVD WC-based coatings by Di Maio, D, Roberts, S

“…Results of hardness testing on thin WC-based coatings, using nano-indentation, Vickers and Knoop indenters, are compared. © 2005 Taylor and Francis Ltd.…”

Fracture toughness, surface flaw sizes and flaw densities in Al2O3 by Franco, A, Roberts, S, Warren, P

“…Fracture toughness values were also determined by Vickers indentation over a range of loads; the Klc values determined from the Hertzian tests were consistent with the trends in Klc with crack size from the Vickers indentation tests. …”

Indentation creep and anisotropy in magnesium oxide and germanium by Everitt, N, Everitt, Nicola Mary

“…However a region of no indentation creep was exhibited between 750°C and 1050°C for both Vickers and Knoop indentations. This has not been reported in previous studies. …”

HARDNESS ANISOTROPY AND POLARITY IN INDIUM-ANTIMONIDE by Roberts, S

“…Hardness tests were performed on left brace 111 right brace and left brace 001 right brace faces of InSb in the temperature range 20-400 degree C. A Vickers indenter was used on the left brace 111 right brace faces; it was found that the In face was harder than the Sb face at all temperatures. …”

Thermal shock resistance of sintered alumina/silicon carbide nanocomposites evaluated by indentation techniques by Maensiri, S, Roberts, S

“…In the first technique, "indentation thermal shock" measurements were made of the extension of median/radial cracks around Vickers indentations after quenching from various temperatures (up to 480°C) into a bath of boiling water. …”

Influence of surface cracks on Hertzian fracture by Warren, P, Hills, D, Roberts, S

“…The Hertzian indentation test is an alternative to the more familiar Vickers indentation test for the evaluation of the fracture properties of brittle materials. …”

HIGH-TEMPERATURE MICROHARDNESS STUDY OF THE BRITTLE-DUCTILE TRANSITION IN TITANIUM CARBIDE by Serbena, F, Williams, W, Roberts, S

“…The brittle-ductile transition (BDT) has been studied in titanium carbide single crystals using high-temperature Vickers hardness. The indentations were made on the (100) surface in the temperature range 20-900°C under vacuum. …”

Indentation-induced crack interaction in alumina ceramics by Twigg, P, Davidge, R, Riley, F, Franco, A, Roberts, S

“…Polycrystalline aluminas of tailored composition and grain size, prepared using liquid-phase sintering aids based on the Al2O3-CaO-SiO2 and Al2O3-MgO-SiO2 systems, have been indented at loads close to their critical fracture limit P*, using closely spaced arrays of low-load Vickers indentations. The propagation of cracks caused by indentation is influenced by internal residual stresses at alumina grain boundaries developed during cooling from the processing temperature, and primarily the result of thermal expansion mismatches between the alpha-Al2O3 crystals of the matrix and an intergranular glass of composition related to that of the sintering aid. …”

Irradiation effects on the deformation of oxide dispersion strengthened steels by Grieveson, E

“…The matrix of four materials and five implantation conditions was analysed using the following experimental techniques: nanohardness indentation, Vickers hardness testing, micropillar compression, microcantilever bending, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX).…”

DOPING EFFECTS ON INDENTATION PLASTICITY AND FRACTURE IN GERMANIUM by Roberts, S, Pirouz, P, Hirsch, P

“…Vickers micro-indentation tests have been performed in the temperature range 20 to 420° C on the {0 0 1} surfaces of germanium crystals of three different dopings: "intrinsic", heavily doped p-type and heavily doped n-type. …”