As proposed by Lawn and Marshall an estimative of Brittleness index could be done by the relationship between Vickers hardness
and [K.sub.Ic] (VH/[K.sub.Ic]).
In the zone having a 12.5 [micro]m depth from the surface where the Vickers hardness
is 500HV or higher, a white oxygen diffusion layer is noticeable.
Micro Vickers hardness
. Process of testing the hardness was done on Micro Vicker hardness testing machine (Model No.402 MVD), which is appropriate for determining the hardness of brittle materials, such as tooth structure.
Figure 6 shows the Vickers hardness
of various mole percentages of dense Zn-doped BCP.
In both cases a Vickers pyramidal indenter was used; the results are presented on the Vickers hardness
scale (200 HV to 400 HV) in Figure 8.
Sintered disc samples are then used to determine bulk density and Vickers hardness
. Disc samples are polished on a polishing machine with grinding papers of different roughness (120,240,600, and 800 CC-Cw) and finally are polished using diamond paste of 6 microns and a polishing cloth.
A FM-700 type microscopic Vickers hardness
tester (FutureTech, Japan) was used to measure the microharnesses of nPCD compacts.
Shimadzu's new HMV-G Series of Micro Vickers hardness
testers provides an operator-friendly, cost-effective solution with automatic length measurement, which is quickly becoming the new standard in the research and development of new materials.
Zwick Roell Indentec has added a software option for image analysis on its automatic and semi-automatic Vickers hardness
Influence of pre-heat treatment and different light-curing units on Vickers hardness
of a microhybrid composite resin.
The popularity of this test spawned a number of test scales, including the Vickers hardness
test (1921), the Rockwell test scale (conceived in 1908), and the Knoop hardness test (1939).