Dislocation Structure Evolution in Low-Stability States of Solid Solutions of Alloys Under Their Deformation

Russian Physics Journal - The results of a study of the dislocation structure evolution in polycrystals of homogeneous solid solutions in low-stability states in Cu-Mn-based alloys with FCC crystal...     

Phase Composition and Thin Structure of Steel Surface after Plasma Electrolytic Carbonitriding

Russian Physics Journal - Using the transmission electron microscopy of thin foils the paper studies the phase composition and fine structure of 0.18С–1Cr–3Ni–1Mo–Fe...     

Critical Grain Size at Meso-Level after Deformation of Polycrystalline Metals and Alloys in Low-Stability State

Russian Physics Journal - The paper deals with the dislocation and dislocation-disclination substructures of polycrystalline FCC alloys Cu–Al and Cu–Mn modified by tensile deformation....     

Procedure for describing the deformation of materials to fracture under conditions of near-superplasticity

Novosibirsk. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, No. 1, pp. 149–157, January–February, 1995.     

Grooved conjugation ferrite element for ultrasound heating of a biological tissue phantom

A possibility of using a parametric ultrasound phase conjugation system with a grooved ferrite element for hyperthermal heating of a biological tissue phantom is experimentally investigated. The grooved surface of the ferrite element improves the quality of phase conjugation. With focused conjugate beams, this is supposed to lead to an increase in the ultrasound intensity and accordingly to more effective heating of the medium due to ultrasound absorption. The results of the investigation prove this supposition: ultrasound heating by 8.0°C in about 80 s is obtained for a sample with an inserted thermocouple placed between a focused piezoelectric transducer, which radiated a test wave with a frequency of 5.0MHz, and a system for phase conjugation and amplification of ultrasound.     

Asymmetry of temperature dependences of electrical resistivity under B2–B19′ and B2–R–B19′ martensitic transformations in TiNi-alloys

The temperature dependences of electrical resistivity through the region of martensitic transformations in the alloys based on titanium nickelide are shown to exhibit pronounced asymmetry under conditions of direct and reverse transformations. It is assumed that this behavior is due to different character of temperature dependences of electrical resistivity in the austenite and martensite phases, which provide an explanation for this marked asymmetry.     

Local heating of a liquid-like medium by a phase-conjugate ultrasound beam with self-adaptive focusing

Local heating of a liquid-like medium by means of self-adaptive focusing of a high-power phase conjugate ultrasound wave has been experimentally implemented. A sample of organic silicon polymer with a reflecting inhomogeneity was placed in water and exposed to a plane ultrasound beam so as to make the reflected acoustic field partially to enter the phase conjugation device. A parametrically amplified and conjugate wave was self-adaptively focused back to the inhomogeneity. Thermocouple measurements revealed ultrasound heating, which was localized near the inhomogeneity and depended weakly on its position within the aperture of the incident ultrasound beam. Themaximum heating value was about 6.5°C in 120 s with a frequency of ultrasound of 4.75MHz and a mean power of phase conjugate wave of about 0.1W.     

Focusing of a nonlinear phase-conjugate ultrasonic wave transmitted through a phase-inhomogeneous layer

The propagation of a nonlinear phase-conjugate ultrasonic wave through a layer introducing random phase aberrations is studied experimentally. The wave is generated by an overthreshold parametric phase-conjugating ultrasonic amplifier. It is shown that, with the extent of nonlinearity achieved for the conjugate wave, the phase locking of harmonics is retained and, as a consequence, a compensation of the distortions introduced by the layer takes place. The possibility of an automatic focusing of a nonlinear phase-conjugate wave propagating in an inhomogeneous medium is demonstrated, which is important for practical applications.