Microstructure and mechanical properties of epoxy resin/carbon black composites synthesized by in situ condensation polymerization of monomers in the presence of carbon black particles were investigated. SEM observation showed that carbon black particles were well dispersed in the epoxy resin matrix. The composite with 1 wt. % carbon black had the electrical resistivity of approximately 108.7 Ω•cm. The composites exhibited an a percolation threshold at carbon black content about 4 wt.%, indicating the existence of a path of percolation by connecting carbon black particles. Bending strength dramatically increased to a maximum value of 133.4MPa and then slowly decreased with content of carbon black increasing. Shore hardness increased gradually with content of carbon black and came to 23.3HD at carbon black 10 wt.%.

Bulk nanocrystalline Fe-Al based alloys with 5, 10 and 15 wt. % Ni were prepared by aluminothermic reaction. The alloys were analyzed by electron probe microanalyzer, X-ray diffraction and transmission electron microscope. Compressive yield strength and hardness of the alloys were tested. The experimental results showed that all of the alloys consisted of Fe-Al-Ni matrix and small amount of Al2O3 sphere. The matrix phases of the alloys with 5 and 10 wt. % Ni had disordered α-Fe solid solution, while the matrix phases of the alloys with 15 wt. % Ni had disordered α-Fe solid solution, NiAl phase and Fe3AlCx phase. Average grain sizes of the matrix phases of the alloys were about 20 nm. The alloys with 5 wt.% Ni had the best plasticity, but the alloys with 15 wt. % Ni had the highest yield strength and hardness. Yield strength of those alloys is higher than that of coarse-grained Fe3Al.

The paper studies various rolling schedules implemented at 500°C (incl. direct, reverse, and cross rolling) and their effect on the structure formation and mechanical properties in AISI 304L stainless steel samples. Both TEM and SEM research techniques were applied. An ultrafine grain-subgrain microstructure was found to be formed inside elongated original grains. Rolling-processed microstructural elements were close in their size with the minimum value observed after a reverse rolling (240 nm). Mechanical properties were studied using microhardness measurements and tensile testing revealing a considerable increase in strength accompanied by a density reduction upon deformation. The strength values in the material subjected to all three rolling schedules are relatively close to the highest yield strength and ultimate tensile stress observed after reverse rolling with a strain degree of 70%.

Bimodal nano/micro grain structure is prepared in 1020 carbon steels by aluminothermic reaction casting. It is found that the steel consists of a nanocrystalline ferrite matrix and micro-crystalline pearlite phase. The differences in the precipitation behaviors of ferrite by proeutectoid and pearlite transformed from residual austenite are conductive to bimodal microstructure formation. For different substrates of copper and glass, respectively, lamellar space of the pearlite was about 150 and 110 nm, and average grain size of the ferrite matrix is about 35 and 34 nm. Brinell Hardness, compressive and tensile yield strengths, and total elongation are 180 and 162 HB, 400 and 600 MPa, 275 and 230 MPa, 20 and 10%, respectively.

The effects of annealing on microstructure and mechanical properties of bulk nanocrystalline Fe3Al based alloy with 10 wt. % Ni prepared by aluminothermic reaction have been investigated. It was found that crystal structure of the alloy did not change after annealing at 600 and 800 °C, while it changed to ordered B2and nanocrystalline grains orientations became random after annealing at 1000 °C. Average grain sizes of the alloy changed a little after annealing at different temperatures. The alloy after annealing had a large plastic deformation in compression at room temperature and the alloy annealed at 800 °C had the highest compressive yield strength of 1351 MPa. The alloy without annealing had much lower flow stress and good creep property in compression at 800 and 1000°C.