MODE OF MEASURING OF HARDNESS OF METALLIC SAMPLES Russian patent published in 2007 - IPC G01N3/44 

FIELD: the invention refers to measuring technique.

SUBSTANCE: the essence is in introducing of an indenter into the sample under a measuring loading. The beginning of reading is registered. The loading is increased to testing value. Exposure is made under this loading. After exposure the loading is reduced to a value less then the measuring load and additionally the loading is increased to measuring. The depth of the print of the indenter is measured and the hardness of metals is defined according to its depth. Relative changes of the sample's form or the volume of the print, field temperature and the thermal flow caused by elastic-plastic deformation are registered in the moments of reducing or removing of the load. On these readings the value of the testing loading is defined on the level of elastic-plastic deformation. The surface of the print is scanned separately with optical radiation in the chosen system of coordinates. The optical surface is matched with a longitudinal temperature profile in the same system of coordinates with a chosen sampling increment and thermal-holographic profiles are registered. Inner defects are defined on changing of a spatial gradient of the temperature in the volume of the sampling increment on the distance of falling the temperature on no less then in two times from the maximal temperature and on values of corresponding derivatives it is possible to judge about physical-mechanical and physical-chemical deviations characterizing the sample on inner overstrain, macro- and micro-defects, sphericity, roughness, grain, durability, plasticity, viscosity, heterogeneity.

EFFECT: expands functional possibilities and stability of readings.

3 dwg