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The effects of ultrasonic treatment in ball mill (ultrasonic milling) on structure-phase characteristics and magnetic properties of fine-dispersed powder mixtures (FDPMs) of copper with aluminium and manganese are studied by X-ray analysis and magnetometry. As shown, after ultrasonic milling the phase state and dispersity of (Cu + Al, Mn) FDPMs remain almost unchanged, though the dispersity of the phase components are essentially increased. During the ultrasonic milling process the concentrations of aluminium, manganese, and copper in FDPMs remain almost unchanged in compare with the initial values that witnesses to a high thermal stability of FDPMs. As assumed, this observation is related with the presence of the oxide films on particles' surface, which inhibit the diffusion processes. The absence of equilibrium ferromagnetic phases Cu2MnAl and MnAl in Cu + Mn + Al and Mn + Al FDPMs are also connected with the presence of metal oxides in the powder mixtures and with the influence of the size factor, which result in essential shifts of the lines of the phase equilibrium in the diagrams of states. As also shown, the FDPMs have ferromagnetic properties both in the initial state and after ultrasonic milling. Their specific magnetizations are in the interval of 0.3-4.0 A⋅m2/kg. As assumed, ferromagnetic properties of the (Cu + Al, Mn) FDPMs are caused by a high quantity of microstructural defects and by the size factor. [ABSTRACT FROM AUTHOR]

Purpose. Investigate the passage of ultrasonic waves through a two-layer material with a complex structure with non-contact control of its technological parameters. Methodology. A non-contact ultrasonic method was used in the work to control technological parameters of materials with a complex structure, which takes into account the attenuation of ultrasonic waves. Findings. It is substantiated that the attenuation of an ultrasonic signal for a material with significant pores during its transverse sounding can be neglected compared to attenuation in a material without through pores. The results of studies of the influence of the thickness of a material with pores on the amplitude ratios of ultrasonic waves are presented. Originality. The dependences of the amplitudes of ultrasonic waves are obtained, one of which passes through a two-layer continuous material, and the other passes through a two-layer material with pores, taking into account the dependence of their attenuation on the thickness of the material. In this work, we obtained the dependences of the phase shift of ultrasonic waves, which were reflected from a two-layer material without pores, and waves reflected from a two-layer material with pores, on the total thickness of the controlled material, if we compare the phase of these waves with incident vibrations. Also obtained are the dependences of the change in wave amplitudes over time for a pulsed ultrasonic signal passing through a controlled material. Practical value. It is proposed to use a pulsed ultrasonic signal for operational non-contact control of technological parameters of bilayer materials with a complex structure. The analysis showed that the obtained expressions for pulsed ultrasonic signals that can interact with porous materials can be used to create new methods and means of non-destructive non-contact control of technological parameters of materials with a complex structure. The aforementioned will make it possible to create complex integrated and universal contactless control devices for various technological parameters for composite materials with pores, which today are subjected only to destructive contact control, which does not allow operational monitoring directly at the plant. [ABSTRACT FROM AUTHOR]