title: Alternate stresses and temperature variation as factors of influence of ultrasonic vibration on mechanical and functional properties of shape memory alloys.
abstract: It is known that the main factors in a variation in the shape memory alloy properties under insonation are heating of the material and alternate stresses action. In the present work the experimental study of the mechanical behaviour and functional properties of shape memory alloy under the action of alternate stresses and varying temperature was carried out. The data obtained had demonstrated that an increase in temperature of the sample resulted in a decrease or increase in deformation stress depending on the structural state of the TiNi sample. It was shown that in the case of the alloy in the martensitic state, a decrease in stress was observed, and on the other hand, in the austenitic state an increase in stress took place. It was found that action of alternate stresses led to appearance of strain jumps on the strain-temperature curves during cooling and heating the sample through the temperature range of martensitic transformation under the constant stress. The value of the strain jumps depended on the amplitude of alternate stresses and the completeness of martensitic transformation. It was shown that the heat action of ultrasonic vibration to the mechanical behaviour of shape memory alloys was due to the non-monotonic dependence of yield stress on the temperature. The force action of ultrasonic vibration to the functional properties was caused by formation of additional oriented martensite.
authors.affiliation: Saint-Petersburg State University, Universitetsky pr. 28, Saint-Petersburg 198504, Russia. Electronic address: spb@smel.math.spbu.ru.
authors.forename: Sergey
authors.initials: S
authors.lastname: Belyaev
authors.forename: Alexander
authors.initials: A
authors.lastname: Volkov
authors.forename: Natalia
authors.initials: N
authors.lastname: Resnina
mesh_terms: D000497:Alloys / Q000737:chemistry / Q000528:radiation effects; D055119:Elastic Modulus / Q000528:radiation effects; D006244:Hardness / Q000528:radiation effects; D019220:High-Energy Shock Waves; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry* / Q000528:radiation effects*; D013010:Sonication / Q000379:methods*; D013314:Stress, Mechanical; D013696:Temperature; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects*; D014732:Vibration
chemical_list: D000497:Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium
keywords: Shape memory alloys; Shape memory effects; Ultrasonic