Papers by Keyword: Magneto-Plastic Effect

Abstract: The paper presents a brief review of experimental results obtained in the study on the effect exerted by Ni-additives (0.4 and 1.0 wt. %) on the kinetic processes occurring during the artificial aging of copper-beryllium alloys under a constant magnetic field. Probable atomic mechanisms of the effects observed are also discussed.

Abstract: Kinetics of changes of microstructure of beryllium bronze BrB-2 in d decomposition process of supersaturated solid solution in the pulse magnetic field with 0 – 7 Hz frequency with pulse intensity amplitude 318.4 кA/m (4 kOe) and magnetic field constant component 238.8 кA/m (3 kOe) under the temperature 350 °С and ageing duration 1 hour was investigated by microhardness measurements and X-ray diffraction. Frequency dependences of microhardness, lattice parameter, beryllium concentration in a residual matrix, size of coherent scattering blocks, dislocations density and the value of relative microdeformation of the matrix blocks under ageing in the pulse magnetic field and without it have been investigated. Experiment results show that the pulse magnetic field essentially influences the parameters of the fine structure and also physical and mechanical properties of bronze.

Abstract: An influence of a constant magnetic field (MF) with induction up to 15 T upon macroscopic plastic deformation of diamagnetic NaCl single crystals containing paramagnetic Eu impurity was observed. Effects of MF on instability of plastic flow (on the Portevin-Le Chatelier effect) in quenched NaCl:Eu crystals were found. The MF results in a decrease of the yield stress, a decrease of the probability of the instability appearance, and a decrease of the averaged magnitude of the deformation jumps, as well as in a chaotization of the distribution of the deformation jump magnitudes. The latter can be explained by partial plastic relaxation of internal stresses under MF that was confirmed by dislocations displacement induced by internal stresses in MF. The averaged amount of shear bands observed on the surface of the investigated crystals deformed under MF is half of that in reference specimens.

Abstract: In this research, the process of artificial aging of beryllium bronze as diffusioncontrollable process was studied at the temperatures of 250–500 0C, at aging time intervals of 0.17 till 2 hours, in the constant magnetic field and without it by microhardness and residual magnetization methods.