Papers by Author: Yuri V. Sudenkov

Abstract: This work presents experimental studying the effect of processing by severe plastic deformation (SPD) on the thermoelastic and thermoelectric properties of pure aluminum and copper under pulsed laser radiation. The studies were carried out on technical aluminum AD1 (99.3%) and pure copper M1 (99.9%). High pressure torsion (HPT) was used for processing by SPD. After the HPT processing, the materials samples in the form of a plane disk were subjected to pulsed laser radiation focused on the disk center. Pulsed lasers with a wavelength of 1.06 micron and operating in the free laser oscillation mode with pulse duration of 100 microseconds or in the mode of a single pulse with duration of about 10 nanoseconds were used. The thermoelastic and thermoelectric responses of the materials were determined by measuring acoustic waves and the thermoelectric power. The disks with the initial coarse-grained material state were considered as a reference sample, and the disks of the materials after SPD processing were considered as a controlled object. The results demonstrated a very high sensitivity of the parameters of thermoelastic and thermoelectric response to structural changes in the materials. For example, the used HPT mode led to a reduction in the maximum thermoelectric power value for aluminum by 40% and for copper by 35%.

Abstract: The behavior of the ferromagnetic alloy based on Fe-Cr-Co under high-speed loading is presented. Three types of samples were prepared with different pre-treatments: quenching only; quenching and ageing; and quenching and ageing under an intense external magnetic field. The sub-microsecond impact load was created by the installation for the electrical explosion of foils. The developed method of loading allows a pressure pulse to be registered before impact on a flat sample and after its exit to a free surface of this sample. Changes in the mechanical properties of the ferromagnetic alloy with various technologies of preliminary processing before and after shock loading are discussed.

Abstract: Results of experimental investigation of concrete and rocks under high rate loads of microsecond duration (2.5 µs) are presented. Tested samples are rectangular plates (150/150/15 mm) with a notch (70 mm long and 3 mm thick) containing a pre-crack (about 1 mm long). Dynamic loading was created utilizing electric wire explosion technique. An electric wire was placed between the faces of the notch at a distance of 20 mm from the tip of the pre-crack. After the wire explosion the trajectory of the extended crack and the fracture surface were studied. Measured dependence of the crack extension on the loading pulse energy gives the possibility of determining the threshold (minimal) amplitude of the load required to initiate fracture in the studied samples.