METHOD OF DETERMINING THERMOMECHANICAL CHARACTERISTICS OF MATERIALS WITH SHAPE MEMORY EFFECT Russian patent published in 2016 - IPC G01N3/18 

FIELD: metallurgy.

SUBSTANCE: invention relates to non-destructive testing of materials with shape memory, specifically alloys based on titanium nickelide and can be used in all industries for detection and monitoring of radial stresses thermomechanical return, required to ensure serviceability of compounds in assembly of structures by means of couplings of material with shape memory effect. Method comprises testing a hollow cylindrical sample of circular cross section with an austenitic structure. Method includes pre-measuring sizes of diameter of its inner cavity and height, then cooling cylindrical sample to temperature of formation of martensite structure and in this state it is subjected to deformation by expansion of its inner cavity on a rod with diameter 2-8% larger than that of inner cavity, measured in initial austenitic state. Sample with rod is then heated to temperature of formation of austenite structure, and then force is applied for disconnection of rod and sample and at moment of start of rod from inner cavity of sample fixed value of applied force. Thermomechanical return tension is determined from the ratio.

EFFECT: technical result is a method of determining value of thermomechanical stresses return occurring in radial direction in thermomechanical joints made by means of couplings, made from material with shape memory effect.

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