The Effect of Electron-pulse Modification of the Surface Layer on the Strength Properties of the Ni[3]Al Intermetallic Compound

In this paper it was shown that pulsed electron irradiation forms in the surface layer of the Ni[3]Al intermetallic compound samples a columnar crystal structure oriented perpendicular to the irradiated surface. The dimensions of the crystals of the columnar structure and the depth of the surface layer modification depend on the power density and the duration of the irradiation pulses - with power density increasing , the dispersion of the columnar structure increases, with increasing duration of irradiation pulses, the depth of the surface layer structure modification increases. Modification of the surface layer structure improves the strength properties of Ni[3]Al intermetallic compound samples

The Effect of Electron-pulse Modification of the Surface Layer on the Strength Properties of the Ni[3]Al Intermetallic Compound

In this paper it was shown that pulsed electron irradiation forms in the surface layer of the Ni[3]Al intermetallic compound samples a columnar crystal structure oriented perpendicular to the irradiated surface. The dimensions of the crystals of the columnar structure and the depth of the surface layer modification depend on the power density and the duration of the irradiation pulses - with power density increasing , the dispersion of the columnar structure increases, with increasing duration of irradiation pulses, the depth of the surface layer structure modification increases. Modification of the surface layer structure improves the strength properties of Ni[3]Al intermetallic compound samples

Influence of the Thermal-force Effect on the Process of Hightemperature Synthesis of the Ni[3]Al Intermetallic Compound

In this work, the intermetallic compound Ni[3]Al was obtained by high-temperature synthesis under pressure at various values of the preliminary pressure on the initial powder mixture (3Ni+Al). The study of pressure-time and displacement-time diagrams gave a coherent picture of the synthesis passage over time. It was found that an increase of preliminary pressure leads to a decreasing of the powder compacts porosity. In this regard, the smallest displacement of the press plunger after initiating the synthesis reaction in the powder compact was observed at the highest value of the preliminary pressure on the compact. The role of preliminary pressure on the initial powder mixture in the process of the grain structure formation of the Ni[3]Al intermetallic compound synthesized under pressure was determined

Structural state scale-dependent physical characteristics and endurance of cermet composite for cutting metal

A structural-phase state developed on the surface of a TiC/Ni-Cr-Al cermet alloy under superfast heating and cooling produced by pulse electron beam melting has been presented. The effect of the surface's structural state multimodality on the temperature dependencies of thefriction and endurance of the cermet tool in cutting metal has been investigated. The high-energy flux treatment of subsurface layers by electron beam pulses in argon-containing gas discharge plasma serves to improve the endurance of metal cutting tools manifold (by a factor of 6), to reduce the friction via precipitation of secondary 200 nm carbides in binder interlayers. It is possible to improve the cermet tool endurance for cutting metal by a factor of 10-12 by irradiating the cermet in a reactive nitrogen-containing atmosphere with the ensuingprecipitation of nanosize 50 nm AlN particles in the binder interlayers

Nanostructured Hardening of Hard Alloys Surface Layers Through Electron Irradiation in Heavy Inert Gas Plasma Conditions

The paper presents research and experimental findings which prove that metal ceramic composite surface layer contains micro constituents' hierarchies in the form of secondary nano sized inclusions inside ceramic phases. These inclusions have typical dimensions from several tens to several hundreds of nano meters. It has been shown that multi level structure-phase condition, developed in a nano sized area, effects physical and tribological properties of a metal ceramic composite surface layer

Exploring the relationship of brown adipose tissue to bone microarchitecture using 7T MRI and micro-CT

Background. Brown adipose tissue (BAT) is involved both in energy production and bone metabolism. The purpose of this study was to analyze the relationship between BAT and microarchitecture at cancellous and cortical bone using Kunming mice and the methods of 7T magnetic resonance imaging (MRI) combined with micro-CT. Methods. Twenty-four female Kunming mice were examined by 7T MRI and measured T2* relaxation time on the deep and superficial interscapular BAT (iBAT) and subcutaneous white adipose tissue (sWAT). Cancellous bone microarchitecture of the distal femur and cortical bone of the middle femur were examined by micro-CT. A paired t-test was used to analyze the differences in T2* values between iBAT and sWAT. The correlation between BAT T2* values and bone microstructure parameters were analyzed using Pearson’s correlation. Results. T2* values of the deep and superficial iBAT (6.36±3.31 ms and 6.23±2.61 ms) were significantly shorter than those of sWAT (16.30±3.05 ms, tdeep iBAT=- 10.816), tsuperficial iBAT=-12.276, p<0.01). Deep iBAT T2* values were significantly and negatively correlated with bone volume, cancellous thickness, and bone thickness (Th) and trabecular thickness (Tb.Th) of the cancellous bone of femur. Deep iBAT T2* values were significantly and positively correlated with the structural model index of cancellous bone of femur. Deep iBAT T2* values were significantly and negatively correlated with bone mineral density of the cortical bone of femur. Conclusions. MRI can distinguish the two adipose tissues from each other. T2* values of BAT were lower than WAT on MRI. BAT related bone remodeling was more correlated with the microstructure of cancellous bone than that of cortical bone