A gradient nanostructured surface layer of about 100 μm in thickness was synthesized on the pure iron induced by surface mechanical attrition treatment (SMAT). The average grain size in the top surface is about 20 nm. The formation behaviors of Fe-Si compound layer were investigated in nanostructured Fe during the electroless siliconizing process. In comparison with the coarse-grained (CG) sample, the thickness of compound layer on the SMAT sample is about twice larger than the CG sample and the diffusion activation energy decreased from 231 kJ/mol to 165 kJ/mol for the sample after SMAT 20 min. Evident inter-diffusion of elements such as Fe and Si could be found under the EDS analysis, suggested the achievement of metallurgical bonding. The porosity appeared at the interface of matrix and Fe 3 Si layer in the CG sample due to Kirkendall effect, however, the bonding of the compound layer and matrix was tighter due to the promotion of the elements diffusion in the SMAT sample. The enhanced siliconizing kinetics is attributed to numerous grain boundaries (GBs) in the nanostructured surface and deformed layer.

Enhancement of siliconizing behaviors in pure iron induced by surface mechanical attrition treatment

A memristor-based VB2 chaotic system: dynamical analysis, circuit implementation, and image encryption

The invention discloses a molten salt non-electrolytic preparation method for an alloying Fe3Si permeability layer improving 2Cr13 martensitic stainless steel abrasion resistance and corrosion resistance surface comprehensive performance, and provides two technical preparation methods of the alloying Fe3Si permeability layer. One method is to use the alloy element Cr in 2Cr13 matrix compositions to prepare a Cr alloyed siliconizing layer with good passivation property, good corrosion resistance and high abrasion resistance. The other method is to prepare Ni, Cu and other design coating systemswith a certain thickness on the matrix surface by an electroplating method, and then obtain (Ni, Cr)-, (Cu, Cr)- and other alloying Fe3Si permeability layers by neutral molten salt non-electrolytic siliconizing. The alloying Fe3Si permeability layer prepared by the method is firmly combined with the 2Cr13 matrix. The corrosion resistance and abrasion resistance of the 2Cr13 steel are improved effectively. Application requirements of different working conditions can be met. The method is simple, the cost is low, and excellent application prospects are achieved.

Molten salt non-electrolytic preparation method for alloying Fe3Si permeability layer improving 2Cr13 stainless steel abrasion resistance and corrosion resistance comprehensive performance

Surface nanocrystallization of pure Fe was performed using an improved surface treatment process. The phase transformation and Si infiltration depth of the pure Fe before and after surface mechanical attrition treatment (SMAT) were compared by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicated that nanocrystallization of Fe surface was achieved using SMAT, which resulted in deeper penetration of Si. Prolonging time of SMAT and Si infiltration also resulted in increasing microhardness, with the hardness first increasing with increasing distance from the surface and then decreasing. Furthermore, longer Si infiltration time, nanocrystallization of Si and longer SMAT time resulted in higher saturation magnetization (MS). The greatest Si penetration depth (150 μm), maximum hardness (280 HV), and maximum MS (1.849 × 106 A/m) were achieved after SMAT for 45 min and Si infiltration for 9 h. The interaction between adjacent grains after surface nanocrystallization leads to a region of the magnetic domain wall structure located at the grain boundary, which causes the remanence enhancement effect.

Effect of surface self-nanocrystallization and Si infiltration on Si diffusion behavior, hardness and magnetic properties of pure Fe

A 300 MHz MOS-only memristor emulator

The invention belongs to the field of material preparation, in particular to a method for preparing high-silicon steel from low-silicon steel. The method comprises the following steps: a, using a low-silicon steel hot-rolled plate with a smooth surface as a base material, and carrying out cold rolling so as to obtain a thin plate; b, carrying out acid pickling on the thin plate so as to remove oil stains and an oxide film on the surface; c, in a temperature range of 450-550DEG C, carrying out thermal insulation on the cold-rolled thin plate in a solid siliconizing agent for 20-30 minutes; d, in a temperature range of 750-820DEG C, carrying out solid siliconizing on the thermally insulated thin plate for 10-30 minutes in the solid siliconizing agent; e, rolling the thin plate at a temperature of 350-450DEG C; f, at a non-oxidization atmosphere, carrying out diffusion annealing on the siliconized thin plate at a temperature of 850-1100 DEG C for 30-480 minutes; and g, under nitrogen protection, rapidly cooling the thin plate subjected to diffusion annealing to a room temperature and coating a MgO coating. The method is characterized by low raw materials and simple processing and treating. The problems of steel band surface serious corrosion and Fe losses, caused by high Cl-ion concentration in the process of preparing the high-silicon steel by a vapor deposition process are solved.

Method for preparing high-silicon steel from low-silicon steel

Mathematical analysis and circuit emulator design of the three-valued memristor

Heat stability and siliconizing behavior of surface nanostructure of silicon steel induced by asymmetric rolling

An FPGA-based memristor emulator for artificial neural network

Geographic distance, landscape heterogeneity and migratory connectivity influence population genetic structure of farmland-dependent wintering birds and their conservation

Gang Liu

Papers

Method for preparing high-silicon steel from low-silicon steel

Mathematical analysis and circuit emulator design of the three-valued memristor

Heat stability and siliconizing behavior of surface nanostructure of silicon steel induced by asymmetric rolling

An FPGA-based memristor emulator for artificial neural network

Geographic distance, landscape heterogeneity and migratory connectivity influence population genetic structure of farmland-dependent wintering birds and their conservation