Creation of wear-resistant near-surface-layers with inhomogeneous structure on NiTi alloy by ion implantation technology

Based on the results of X-ray structural analysis, changes in the crystalline structure during natural aging and laser annealing, which occurred in near-surface layers of epitaxial films of LaGa-substituted Iron-Yttrium Garnet, implanted by F+ ions, were studied. The processes that occur during the ion implantation by F+ in ferrite-garnet films, and the processes that accompany the low-temperature aging of ion-implanted films are considered. From the experimental rocking curves, obtained immediately after ion implantation, after the laser irradiation and after several years, strain profiles were determined. Two stages in the changes of the crystalline structure of the nearsurface disturbed layer over time are revealed. During the first of them, the maximum deformation in the ionimplanted layer increased slightly, and on the second it decreased. It was established that the results of laser annealing and natural aging of near-surface layers implanted by F+ ions and laser irradiated LaGa:YIG films depend on the direction from which laser irradiation occurred. However, the result of their total exposure does not depend on the side of laser irradiation.

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Microstructure and Composition of Surface Layers Formed by Ion Implantation of Nitrogen in High-Purity Aluminum

MRS Proceedings ◽

10.1557/proc-100-157 ◽

1988 ◽

Vol 100 ◽

Author(s):

Robert C. Mccune ◽

W. T. Donlon ◽

H. K. Plummer ◽

L. Toth ◽

F. W. Kunz

Keyword(s):

Ion Implantation ◽

Ion Beam ◽

Pure Aluminum ◽

Surface Region ◽

Nuclear Reaction Analysis ◽

Surface Layers ◽

Near Surface ◽

Transmission Electron ◽

High Purity Aluminum ◽

Nitrogen Contents

ABSTRACTSurface layers with overall thickness <∼300 nm were produced by ion implantation of N+ or N2+ at energies of 50 or 100 keV in 99.99% pure aluminum. These surfaces were characterized by scanning and transmission electron microscopy, Auger electron spectroscopy, Rutherford backscattering, nuclear reaction analysis and particle-induced X-ray analysis. At doses above 2×1017 N2/cm2 , blistering of the surfaces was observed along with a reduction in the extent of the coulometric dose retained by the material. Oxygen is believed to be introduced into the near-surface region by a process of reaction and ion-beam mixing, as well as possible CO contamination of the beam. A phase, isostructural with AlN, forms semi-coherently with parent aluminum grains, however, some fraction of the metallic aluminum phase remains in the reaction layer, even at overall nitrogen contents which exceed the stoichiometry of AlN.

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Effect of Irradiation with Si+ Ions on Phase Transformations in Ti–Al System during Thermal Annealing

Coatings ◽

10.3390/coatings11020205 ◽

2021 ◽

Vol 11 (2) ◽

pp. 205

Author(s):

Zhuldyz Sagdoldina ◽

Bauyrzhan Rakhadilov ◽

Sherzod Kurbanbekov ◽

Rauan Kozhanova ◽

Aidar Kengesbekov

Keyword(s):

Ion Implantation ◽

Crystal Lattice ◽

Phase Transformations ◽

Thermal Annealing ◽

Aluminum Film ◽

Titanium Silicide ◽

Surface Layers ◽

Near Surface ◽

Before And After ◽

Increasing Temperature

The article deals with the effect of irradiation with Si+ ions on phase transformations in the Ti–Al system during thermal annealing. An aluminum film with a thickness of 500 nm was deposited on VT1-00 titanium samples by magnetron sputtering, followed by ion implantation. Samples before and after irradiation with Si ions were annealed in a vacuum of 10−4 Pa in the temperature range 600–1000 °C. It was established that ion implantation reduces the dissolution of Al in α-Ti with the formation of titanium silicides (TiSi2, Ti5Si3) and stabilizes aluminide phases Ti3Al rich in aluminum. As a result, a composite structure based on titanium silicide/aluminide was obtained on the surface of the sample synthesized by complex treatment: deposition, irradiation with Si+, and thermal annealing at the near-surface layers. The formation of the phase-structural state of the implanted layers is associated with the displacement of atoms of the crystal lattice, a result that is reflected in an increase in the size of the crystal lattice and a decrease in microdistortion of the lattice. The opposite effect is observed with increasing temperature. This fact is explained by the relaxation of unstable large grains with an excess of internal energies. At the annealing temperature of 900–1000 °C, a significant increase in microhardness was observed due to silicide phases.

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