Experimental Observation of the Temperature at the Liquid/Gas Interface

Experimental studies on measurements of the temperature profile in the vicinity of the evaporating distilled water layer were carried out. The temperature was measured with a chromel-alumel thermocouple, when it moves under the action of the precision actuator directed perpendicular to the evaporating layer. According to the experimental results the fluctuation in temperature of the air and liquid was found in the immediate vicinity of the liquid/gas interface. However, temperature jumps near the interface was not observed

Modification of 40X13 steel at high-intensity nitrogen ion implantation

This paper presents the results of the formation of deep modified layers in 40X13 steel using a high-intensity repetitively pulsed nitrogen ion beam with a current density up to 0.25 A/cm2. An arc generator with a hot cathode provided the DC nitrogen plasma flow. A plasma immersion approach was used for high-frequency, short-pulse very intense nitrogen ion beam formation. A grid hemisphere with radii of 7.5 cm was immersed in the plasma. Negative bias pulses with an amplitude of 1.2 kV, a pulse duration of 4 µs, and a pulse repetition rate of 105 pulses per second were applied to the grid. The substrates were implanted at the temperature of 500 °C and various processing times ranging from 20 to 120 minutes with 1.2 keV nitrogen ions using a very-high current density up to 0.25 A/cm2 ion beams. The work explores the surface morphology, elemental composition, and mechanical properties of deep-layer modified 40X13 steel after low ion energy, very-high-intensity nitrogen ion beam implantation

Gas-discharge plasma application for ion-beam treatment of the holes' inner surfaces

The possibility to modify the holes and pipes' inner surface with focused highintensity low-energy ion beams was first shown in this work. The studies were carried out using an axially symmetric single-grid system for the ions' extraction from a free plasma boundary with subsequent ballistic focusing of the ion beam. Ion implantation of the inner surface was carried out in the region of the ion beam defocusing. The studies considered the effect of a nitrogen ions' beam with energy of 1.4 keV on the inner surface of a tube with a diameter of 20 mm made of stainless steel AISI 321. The beams were formed with a repetition rate of 40 kHz and pulse durations of 5, 7.5 and 10 µs. It is shown that the mutual deposition of the sputtered material on the tube' opposite sides partly compensates for ion sputtering. As a result of implantation of the inner surface of a pipe made of stainless steel AISI 321, the nitride layers with a thickness of more than 15 microns with a nitrogen dopant content of 22-30 at.% were obtained

Nitriding of steel 40x with a high-intensity ion beam

The results of experimental and theoretical studies of the regularities and features of the modification of steel 40X with high-intensity beams of low-energy nitrogen ions are provided. The study of the effect of high-intensity, ultra-high-fluency implantation of low-energy nitrogen ions at temperatures of steel 40X samples in the range of 450-650 °C are presented. It is established, that the width of the nitrided layer, during 60 minutes, depends both on the temperature implantation regime and on the ion current density, the maximum depth of nitrogen penetration of 180 ?m was observed at a target treatment temperature of 500 °C. The results of numerical simulation agree with the experiments and allow predicting the structure of surface layers when the geometry of the system and parameters of a high-intensity low-energy beam of nitrogen ions change

Low-energy plasma-immersion implantation of nitrogen ions in titanium by a beam with ballistic focusing

The results of experiments on low-energy implantation of nitrogen ions into VT1-0 titanium alloy are presented. Processing was performed by a nitrogen ion pulsed beam obtained using a ballistic ion focusing system. An ion source was a nitrogen plasma of the non-self-sustained gas arc discharge with a thermionic cathode. It has been shown that when the specimens are processed in such a system, hardness of the surface increases from 1.5 to 2.5 times. In addition, the surface of the specimens undergoes ion etching which causes the formation of an etching cavity whose profile depends on the ion effect parameters

Modification of stainless steel by low-energy focused nitrogen ion beam

The results of experiments on the modification of SUS 321 stainless steel by a nitrogen ion beam extracted from a gas plasma of the non-self-sustained arc discharge with hot cathode PINK are presented. Extraction and focusing of the beam was carried out through a grid electrode of the definite curvature. When negative electric pulsed bias is applied to the grid electrode and a specimen located under the same potential, a ballistically focused nitrogen ion beam is formed. As a result of the processing, a nitride layer is formed on the surface of stainless steel with an increased hardness compared to the initial one

Modification of stainless steel by low-energy focused nitrogen ion beam

The results of experiments on the modification of SUS 321 stainless steel by a nitrogen ion beam extracted from a gas plasma of the non-self-sustained arc discharge with hot cathode PINK are presented. Extraction and focusing of the beam was carried out through a grid electrode of the definite curvature. When negative electric pulsed bias is applied to the grid electrode and a specimen located under the same potential, a ballistically focused nitrogen ion beam is formed. As a result of the processing, a nitride layer is formed on the surface of stainless steel with an increased hardness compared to the initial one

Modification of stainless steel based on synergistic of low-energy high-intensity ion implantation and high-current electron beam impact on the surface layer

The results of experiments on low-energy implantation of AISI 321 stainless steel by nitrogen ions are presented. The treatment was carried out by a pulsed beam of nitrogen ions obtained using a ballistic ion focusing system. The surface modification occurs with the formation of a two-layer structure, which is typical for ion-plasma nitriding processes of stainless steels. The thickness of the modified layer can reach 27 ?m after 1 hour of ion-plasma treatment. The influence of subsequent modification of the ion-doped layer by the action on the surface of the pulsed high-current electron beam of microsecond duration is studied. The work presents the results of the studying the regularities of changes in the depth distribution of dopants, microstructure and phase composition of the modified and matrix layers by optical metallography, diffraction analysis and transmission electron microscopy