Electrical Discharge Machining by Structural-Steel Electrodes

Russian Engineering Research - An approach is outlined to selecting conditions of electrical discharge machining such that coatings with the required functional properties are formed on the working...     

A Thin-Film Platform for Chemical Gas Sensors

In the study, a technique for formation of planar microheaters that make it possible to heat an active zone to a temperature higher than 500°С is proposed and successfully implemented. The developed heating elements are distinguished by low power consumption, short response time, and extremely high resistance to impact loads. The synthetic approaches used in the work (anodic oxidation, photolithography, and magnetron sputtering) feature manufacturability and scaling simplicity. This makes planar heating elements a promising platform based on which semiconductor and thermocatalytic sensors of toxic and explosive gases may be created.     

Specific Features of Electroplastic Effect in Mono- and Polycrystalline Aluminum

Metal Science and Heat Treatment - The deformation behavior of mono- and polycrystalline aluminum under tension with the impact of different modes of current has been studied. It is shown that the...     

Effect of pulse current on deformability, structure, and properties of NbTi alloy superconductor

The effect of pulsed current on the deformability, structure, and properties of a superconductor based on the Nb-47 wt % Ti alloy after electroplastic deformation is studied. It is shown that the use of a pulsed current during rolling makes it possible to produce a nanocrystalline structure in the alloy and improve its microhardness, as well as to reveal the electroplastic effect in it. It is found that electroplastic deformation does not suppress the superconductivity effect.     

Effect of pulsed current on structure of Al-Mg-Si aluminum-based alloy during cold deformation

The effect of the current density on the formation of the structure of the AD33 Al-Mg-Si alloy during deformation by rolling is studied. It is shown that, at a current density of 30 A/mm², the electroplastic deformation by rolling (EPDR) of the AD33 alloy increases its ultimate strength. A decrease in the deformability of the material with increasing current density to 100 A/mm² and higher is related to the melting of fusible eutectic, which leads to the appearance of microcracks at the grain and subgrain boundaries.     

Modification of aluminum antifriction alloys by carbon nanomaterials

A procedure is developed for modification of the near-surface layers of AO-20-1 alloy (AlSn20Cu, GOST Standard 14113–78) by carbon nanotubes at a depth of 2 μm. Data on the depth distribution of carbon across the near-surface layer are obtained. Mechanical and tribological tests of the modified layer are performed. It has been found that the hardness of the near-surface layer increases by 10–60% at a depth up to 1 μm and the friction coefficient decreases by ∼25 %.     

The size effects in hardness of polycrystalline niobium

The indentation size effect on the hardness of polycrystalline niobium has been studied. A relationship between the material hardness and the indenter mark dimensions is established in a broad range of indentation depths (20 nm–70 μm).     

Optimizing heat treatment regimes for high-strength weldable, sparingly alloyed steels

It is important to devote maximum attention to the heat treatment of temperable high-strength weldable steels (σ_0.2≥700 MPa) in which the expensive alloying elements (Cr, Ni, Mo, etc.) are partially or fully replaced by microadditives (V, Ti, etc.). The present paper concerns the effect of the temperature-and-time heat treatment parameters on the structure, the grain size, and the mechanical properties of sparingly alloyed steel 15G2KhNMFTR. The heat treatment regime is optimized. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 2–5, August, 1998.