The mechanical properties of rolled wire-reinforced aluminum composites at different strain values

Abstract

The analysis of strain parameters at rolling of aluminum composite with wire-reinforcement was carried out in the present experimental work. The roll bonding of two strips of EN AW-5083 alloy with and without diagonal stainless-steel net-reinforcement between them was experimentally proceeded with different reductions. It is analyzed the influence of the rolling reduction in the range from 25% to 55% on the straining of the wires and composite bonding mechanisms. The present experimental work is established and used the set of describing parameters of the net behavior in the composite such as net cell elongation, wire elongation and wire ovalisation. The means of longitudinal and transversal tensile testing, impact testing and microscopic analysis determine the properties of the rolled composite. The analysis of the rolling reduction influence on the mechanisms of bonding formation in the composite its properties and fracture behavior are carried out. Based on the conducted tests, it was established the optimum range of rolling reductions.     

First-Principle Construction of U(1) Symmetric Matrix Product States

The algorithm to calculate the sets of symmetry sectors for virtual indices of U(1) symmetric matrix product states (MPS) is described. The principal differences between open (OBC) and periodic (PBC) boundary conditions are stressed, and the extension of PBC MPS algorithm to projected entangled pair states is outlined.     

Structure and Properties of Iron (Chromium Steel)–High-Carbon Ferrochrome Powder Composites

Powder Metallurgy and Metal Ceramics - The effect of production conditions on the phase composition, structure, and properties of powder materials made of iron and chromium steels (Kh17N2, Kh13M2)...     

Composites based on cBN micron powders structured by carbon binder for the application as functional elements in the working layer of diamond-abrasive tools. Part 2. Composites as bearing elements

The authors discuss the application of composites based on finely dispersed cubic boron nitride micron powders as polycrystalline wear-resistant bearing elements in the working layer of diamond abrasive wheels for the purpose of improving the wheel performance in grinding.     

Composites based on cBN micron powders structured by carbon binder for the application as functional elements in the working layer of diamond-abrasive tools. Part 1. Composite grits as abrasive elements

The paper describes the formation of composites based on finely dispersed cubic boron nitride micron powders structured by a carbon binder. We study the potentiality of using these composites as abrasive elements in the working layer of abrasive wheels to achieve the required wheel performance in grinding.     

Excited-state absorption and anisotropy properties of two-photon absorbing fluorene derivatives

The electronic structure of fluorene derivatives N-(7-benzothiazol-2-yl-9,9-bis-decyl-9H-fluoren-2-yl)-acetamide (1); 9,9-didecyl-2,7-bis-(N,N-benzothiazoyl)fluorene (2); 4,4'-{[9,9-bis(ethyl)-9H-fluorene-2,7-diyl]di-2,1-ethenediyl}bis(N,N-diphenyl)benzeneamine (3); and 4,4',4"{[9,9-bis(ethyl)-9H-fluorene-2,4,7-triyl]tri-2,1-ethenediyl}tris(N,N-diphenyl)benzeneamine (4) were investigated by a steady-state spectral technique, quantum-chemical calculations, and a picosecond pump-probe method. These derivatives are of interest for their relatively high two-photon absorption. The steady-state excitation anisotropy spectra reveal the nature of the ground-state absorption bands. Semiempirical quantum-chemical calculations of the fluorene derivatives (AM1, ZINDO/S) show good agreement with experimental data. The spectral positions and alignment of various electronic transitions of derivatives 1-4 were estimated from their excited-state absorption and anisotropy spectra.     

Arc-Sprayed Iron-Based Coatings for Erosion-Corrosion Protection of Boiler Tubes at Elevated Temperatures

Wire arc spraying is an economically attractive thermal spray process that is especially interesting for the protection of large-scale parts or constructions. This study presents the results of the development and investigation of a number of cored wires based on the Fe-Cr-Al system with minor addition of alloying elements (B, Mn, Ni, Si, Ti, Mg, etc.). The microstructure of the coatings, their electrochemical behavior, and isothermal oxidation performance over a temperature range of 20-700 °C were investigated. Erosion resistance at elevated temperatures was determined with a laboratory test unit under test conditions that have simulated the work conditions in fossil-fuel-fired boilers. It was established that the oxidation resistance and the gas-abrasive wear resistance of arc-sprayed coatings depend mostly on the coating microstructure and homogeneity of element distribution rather than on the general alloying level and microhardness of the coating. A new parameter for coating characterization, namely, the coefficient of chemical microheterogeneity, K _CMH, is introduced to quantify this influence. Formation of the coating microstructure at elevated temperatures and its influence on the protection ability of the coating are discussed.     

The use of bearing elements in the structure of superabrasive wheel working layer to improve the wheel performance

A study is performed to find ways for efficient use of bearing elements in the form of layered compacts or milled Kiborite in the working layer of superabrasive wheels in order to improve the wheel performance in grinding processes.