METHOD TO DETERMINE AREA OF PLASTIC DEFORMATION UNDER FRACTURE IN SAMPLE Russian patent published in 2014 - IPC G01N3/28 

FIELD: measurement equipment.

SUBSTANCE: sample of type 15 according to GOST 9454-78 is used, after damage of the sample by single impact action, using the view of the fracture, they determine extent of viscosity of the investigated material of the sample. Both parts of the sample are divided along the centre in direction from the surface of the fracture along the length of the sample parts. The zone of plastic deformation is investigated under the fracture and into depth of the sample in newly formed surfaces under conditions of flat-deformed development of the crack, and in side surfaces parallel to newly formed ones, under conditions of flatly stressed condition, for this purpose in two parts of the sample they apply prints in the form of paths by an indenter onto investigated surfaces in direction from the surface of the fracture along width and length of the investigated part of the sample, besides, the load value is selected so that deformation is mostly elastic, the pitch between prints and distance between paths are at least three diagonals of the print. Microhardness in prints is identified, the border of the zone of plastic deformation is defined by a transition that separates the microhardness level in the zone of plastic deformation from the level of microhardness of the non-deformed part, and the zone of plastic deformation is defined under the fracture using the formula. In the third part of the sample on investigated surfaces they perform etching in an etching agent, detecting appropriate microstructure in zones of plastic deformation under the fracture and in non-deformed sections under conditions of formation of flatly stressed and flatly deformed conditions, accordingly. The fourth part of the sample is used as a reserve one.

EFFECT: provision of the possibility of complex research of the entire zone of plastic deformation under the fracture in one sample, produced as a result of single impact loading of the sample.

8 dwg