High-power Ion Beam Irradiation Research Articles

Effects of Laser Pretreatment on the Formation of Nanostructured Carbon on the Surface of Chlorinated Polyvinyl Chloride under High-Power Ion Beam Irradiation

Effects of Laser Pretreatment on the Formation of Nanostructured Carbon on the Surface of Chlorinated Polyvinyl Chloride under High-Power Ion Beam Irradiation

Исследование морфологии, химического состава и коррозионной стойкости твердого сплава «TiC–NiTi», модифицированного мощным ионным пучком

The article presents the results of a study of the effect of ion–beam treatment with a high–power ion beam (HPIB) on the change in topography, morphology, chemical composition and corrosion resistance of the surface layers of a tungsten–free hard alloy of the «TiC–NiTi» system. The samples are characterized by scanning electron microscopy, energy dispersive X–ray analysis, scanning probe microscopy, and metallographic analysis. It is revealed that due to the impact of HPIB, the surface layer of the sample undergoes melting with the formation of extended microcracks. At the same time, a decrease in the oxygen concentration from 24,6 to 13,7 at. % is recorded in the surface layer of the sample, and at some points on the sample it is completely absent. This result indicates the dissociation of titanium oxide under the influence of temperatures arising during HPIB irradiation. It is most likely that it is the thermal dissociation of titanium oxide and melting of the sample surface that are the main reasons for the increase in the corrosion resistance of the «TiC–NiTi» system alloy.

Effect of the Preliminary Heat Treatment of Chlorinated Polyvinyl Chloride on the Formation of Carbon Nanofibers on its Surface under High-Power Ion-Beam Irradiation

The effect of a high-power ion beam of nanosecond duration on layers of chlorinated polyvinyl chloride with a catalytic additive (ferrocene), which preliminarily underwent treatment in air or an inert medium in the temperature range 100–400°C, is studied. Heat treatment at 150°C for 1 h is shown to reduce the length of the formed carbon nanofibers by ~20 times. Disk-shaped depressions are observed on the surface of the polymer irradiated after treatment at 200°C due to the removal of a part of the surface layer. These depressions are likely associated with polymer embrittlement during heat treatment. A net-like structure is observed between these depressions. An increase in the treatment temperature to 400°C (in an inert medium) results in the formation of nanofibers with a length not exceeding 0.5 μm. The effect of preliminary heat treatment on the growth of carbon nanofibers and possible mechanisms of their growth under the influence of a high-power ion beam on a chloropolymer containing a catalytic additive is discussed.

Fracture of the Surface Layers of Alumina Ceramics under the Action of a High-Power Ion Beam of Nanosecond Duration

The fracture of surface layers of alumina ceramic (polycor) under the action of a high-power ion beam of nanosecond duration is investigated. The characteristic features of such fracture are determined. An estimation of the thickness of breakaway fragments of the surface layer of the ceramics gives values in the range from 4 to 12 μm at single high-power ion beam irradiation with a current density of 150 A/cm2. Oxygen depletion in the surface layer of the ceramics is established. The effect of irradiation on the structural-phase state of the ceramics is considered. The possible mechanisms of the observed fracture are discussed.

Synthesis of amorphous carbon nanofibers on a surface of commercial polymers under the action of a high power ion beam of nanosecond duration

The irradiation of various commercial polymers (chlorinated polyvinyl chloride, polyvinyl chloride, polyvinyl alcohol, polymethyl methacrylate) by a high-power ion beam of nanosecond duration has been investigated. The amorphous carbon nanofibers formation was detected on the surface of low-cost commercial polymers (chlorinated polyvinyl chloride, polyvinyl chloride) containing a catalyst under the high power ion beam irradiation at room temperature. Various iron compounds (organic and inorganic) were used as catalytic additions. The electron microscopy (scanning and transmission) with an energy dispersive analyzer and Raman spectroscopy were used to investigate the morphologies and structure of irradiated polymers. Carbon nanofibers (CNFs) had a most probable diameter in the range 50-90 nm and a maximum length of up to 10 μm. The maximum CNFs growth rate was estimated as 160 μm/μs. A possible growth mechanism for CNFs is discussed.

Crack formation in soda-lime glass after high-power ion beam irradiation

AbstractThe fractures of a soda-lime glass surface layer were investigated under irradiation by a high-power ion beam of nanosecond duration with different current densities. Two kinds of cracks (perpendicular and approximately parallel irradiated surfaces) have been identified. It is defined that cracks approximately parallel to the surface are localized at a depth of 10 ± 2 µm from the irradiated glass surface after one-time irradiation with a current density of 100 A/cm2. The formation of these cracks was detected within ~170 h after the end of irradiation when irradiated samples were under an air atmosphere. In a vacuum, the growth of these cracks was insignificant. It is shown that irradiation of heated glass or heating of glass started no later than 2–3 min after irradiation can suppress or substantially reduce surface fracture of glass. The possible mechanisms of glass fracture were discussed.

Formation of Nanostructured Carbon Layers on the Surface of Chlorinated Polymers under High-Power Ion Beam Irradiation

A comparative study of the effect of a high-power ion beam of nanosecond duration on layers of reactive industrial chlorinated polymers (chlorinated polyvinyl chloride, polyvinyl chloride) containing a catalytic additive (ferrocene) is carried out. The formation of amorphous carbon nanofiber layers on the surface of chlorinated polymers is revealed. The characteristic diameter and length of nanofibers depends on the type of polymer and irradiation mode and is equal to 30–250 nm and 10 μm, respectively. The growth rate of carbon nanofibers is estimated. Its value might reach ~160 μm/μs. A possible mechanism for carbon nanofiber formation on the surface of chlorinated polymers with the addition of ferrocene under high-power ion beam irradiation is discussed.

Fracture of the surface layers of soda-lime glass under high-power ion beam irradiation

The fracture of the surface layers of soda-lime glass under irradiation with a high-power ion beam of nanosecond duration is investigated. Features of the fracture surface morphology and the depth of spall crack localization in glass are defined. The depth was 10 ± 2 μm after one-time irradiation with a current density of 100 A/cm2. With the use of X-ray diffraction analysis the change in the residual tensile stresses in the surface layers of glass after irradiation is evaluated. The possible mechanisms of the observed fractures are discussed.

Dispersion of thin metal films on dielectric substrates under high-power ion-beam irradiation

The effect of high-power ion-beam irradiation on thin metal (Al, Cu, Cr) films of varying (0.08–1.9 µm) thickness deposited onto dielectric sodium silicate glass and glass-ceramic substrates is investigated. The strong effect of the ion current density and film thickness on the surface morphology under irradiation is found. The features of the dispersion of a chromium thin film having high adhesion to the dielectric substrate by a high-power ion beam are examined.

Influence of copper alloy microheterogeneities on the formation of surface relief under high power ion beam irradiation

Changes in the morphology and surface composition of copper alloys (L63 brass, VB23NTs bronze, and a Cu-Al alloy) containing components with different degrees of volatility, under the action of a high power ion beam of nanosecond duration, are investigated. It is demonstrated that various alloy components affect the formation of surface craters during ion beam irradiation. The probable mechanisms of the observed phenomena are discussed.

Generation of Mechanical Waves in Metals under the High Power Ion Beam Irradiation

The system model «high power ion beam – metal» is suggested. Regularities of impulse formation of mechanical load in the volume of metal target subjected to the action of ion beams of different component composition in the range of power density 107...1010 W/cm2 have been considered. The influence of generation mechanisms on the profile and amplitude-to-time parameters of shock-wave excitation is studied.

Structural evolution of copper alloys under high-power ion-beam irradiation

Structural and phase transformations in copper and its alloys—brass and bronze, irradiated by a high-power ion beam are investigated by X-ray diffraction and scanning-electron microscopy. It is established that the phase reconstruction in brass is caused by the partial removal of zinc from the surface and its diffusion toward the surface from deeper surface layers. Copper and bronze undergo only structural transformations induced by the growth of stresses of type I, II, and III and dislocation density.

Influence of the high-power ion-beam irradiation of a hydroxyapatite target on the properties of formed calcium phosphate coatings

The physical-mechanical of properties of biocompatible calcium phosphate coatings deposited onto titanium and silicon substrates from erosion materials, which are generated by irradiating hydroxyapatite (synthetic and natural) targets by means of the high-power pulsed ion beam of a Temp-4 accelerator, are investigated. A calculation technique for predicting the rate and energy efficiency of deposition using pulsed ion beams is proposed. Their characteristics are analyzed as applied to the formation of calcium phosphate coatings.

Periodical structure formation on a magnesium and aluminum surface under high power ion beam irradiation of nanosecond duration

The formation of periodical structures, and also, micro- and nanoparticles on a polycrystalline magnesium and aluminum surface under high power proton-carbon beam irradiation has been investigated. The spatial parameters of these structures and particle sizes have been determined. The possible mechanisms for periodical structure formation have been considered.

Formation of por-Si/SnOx nanocomposite by high-power ion beams of nanosecond duration

Layers of por-Si/SnO x nanocomposite formed by high-power ion beam irradiation with nanosecond duration have been studied. The results of structural and elemental analyses of these layers are presented. The high sensitivity of this nanocomposite to low NO2 concentrations at room temperature has been revealed.

Formation of disperse particles under high-power ion beam irradiation of metals with a coating

Metal systems based on aluminum and copper coated with nickel irradiated by a high-power ion beam of nanosecond duration have been studied by scanning electron microscopy and local X-ray microanalysis. Dispersed particles of micro- and nanosizes have been found on the surface target. Their composition and formation mechanism differ. It has been shown that microparticles were formed during mixing of film and target atoms and consisted of corresponding components. Nanoparticles were mainly composed of the coating material, and their formation was associated with the dispersion of the Ni film due to the presence of a thin oxide layer on the sample surface. The deposition of Ni ablated by a high-power ion beam can affect the formation of nanoparticles.

Features of high-power ion beam irradiation of nanoporous Si and SiO2

Nanoporous Si and SiO2 melting observed under high-power ion beam irradiation of nanosecond duration was investigated. The sizes of ellipsoidal particles formed in Si and those of holes formed in SiO2 under irradiation were determined. The possible origin of these morphology features was discussed.

Influence of high-power ion beam treatment on the resistance to oxidation in metals and alloys

The influence of high-power ion beam (HPIB) irradiation of metal (copper) and alloys (iron-St20 and titanium-VT6) on the resistance to oxidation has been investigated. The HPIB irradiation with the subsequent oxidation in air has been found to result in the formation of complex oxides on the surface of an alloy. The formation of discontinuous oxide films related to the crater formation under irradiation is the feature of oxidation processes of the irradiated materials. Oxidation resistance has been found to rise in the alloys containing nonmetals as the dopant.

Application of high-power ion beam for silver nanoparticle formation

Silver nanoparticles produced on the surface of soda-lime glass by nanosecond high-power ion beam irradiation were studied by optical methods. Influence of the ion irradiation characteristics on the optical properties of Ag nanoparticles was discussed.

Features of the morphology, defect substructure, and phase composition of metal and alloy surfaces upon high-power ion beam irradiation

Optical metallography, transmission electron microscopy, and phase analysis were used to study the mechanisms of structural transformations in the surface layer of thickness Δ h≈0.2 μm for single crystals and polycrystals of metals and alloys irradiated with high-power ion beams (HPIB's). Characteristic features of the formation of the surface relief and variations in phase constitution and defect substructure of pure metals (Ni, Mo) and single-phase (Mo–Re, Ni 3Al) and double-phase (V–ZrO 2) alloys have been found in relation to the ion beam power density Q=(1–10)×10 7 W/cm 2. Common features and distinctions in the formation of the microstructure of metallic materials belonging to different classes under HPIB irradiation have been revealed. Based on the predictions of a numerical simulation of the time-dependent temperature fields and the melting and evaporation processes in the surface layer, the mechanisms for the phase-structure modification of metal and alloy surfaces are analyzed.