Suchergebnisse

Microhardness tests of samples of technically pure lead are carried out without and with exposure to external magnetic fields with inductions of 0.3 T, 0.4 T, and 0.5 T. The dependences of the C2-grade lead surface microhardnesses on the exposure times in a magnetic field are obtained, thus reflecting the influence of the magnetic field on the plastic characteristics of lead. The exposure time at which the maximum effect on microhardness occurs is revealed. Additional microhardness tests are carried out for cases with magnetic fields with inductions of up to 0.3, 0.4, and 0.5 T and exposure times of 0.25, 0.5, and 1 hour. Following the obtained microhardness data, the plasticity parameters of lead samples in their initial state and after exposure are calculated. The dependences of the plasticity parameters on the exposure times are shown. The behavior of the plasticity parameter of lead samples during their exposure to external magnetic field with induction up to 0.5 T is revealed. The percent changes in the values of microhardness depending on the magnetic field induction are shown.

High-entropy alloys are a new class of materials consisting of at least five elements in an equiatomic or close to equiatomic ratio, which provides them with unique properties. Non-equiatomic high-entropy Fe-Co-Cr-Ni-Mn and Fe-Co-Cr-Ni-Al alloy coatings were applied to the 5083 alloy substrate using wire arc additive manufacturing and the cold metal transfer process. The structure, elemental composition, mechanical and tribological properties of coating / substrate systems were analyzed using modern methods of materials physics. The deposition of FeCoCrNiMn and FeCoNiCrAl HEA coatings on the surface of 5083 alloy was accompanied by the formation of gradients of elemental composition and mechanical properties. A transition layer with a thickness up to 450 μm was formed at the coating / substrate interface located at the coating-substrate boundary. The elemental composition gradient of the transition layer was studied, and a high level of chemical homogeneity of the coating was revealed. Alloying of the coating with substrate elements was observed. The alloying of the substrate with coating elements is accompanied by nonmonotonic changes of element composition in the 500 μm depth layer.