scholarly journals Synthesis of MAX-phases, structure and phase composition of modified layers on titanium alloy VT-1 as a result of electron-beam treatment

2021 ◽  
Vol 2064 (1) ◽  
pp. 012095
Author(s):  
A E Lapina ◽  
N N Smirnyagina ◽  
V M Khaltanova
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
High Vacuum ◽  
Comsol Multiphysics ◽  
Optimal Conditions ◽  
Max Phases ◽  
Software Complex ◽  
Rates Of Change ◽  
Electron Beam Processing ◽  
Composite Layers

Abstract The article presents the results of research and identification of optimal conditions of formation of MAX-phases during treatment of titanium alloy VT-1 by an electron beam in a vacuum. The study of strength characteristics, thermal properties of composite layers was carried out. Thermodynamic study of phase equilibrium in Ti-Si-C and Ti-B-C systems under high vacuum conditions was carried out in order to optimize conditions of formation of functional layers. A mathematical model of the thermal impact of a powerful fast-moving electron beam on the surface of a titanium alloy has been developed VT-1 under the conditions of electron beam processing in the framework of the theory of thermal conductivity using the COMSOL Multiphysics software complex. The obtained numerical results made it possible to investigate the regularity of the distribution of temperatures and their rates of change depending on the action of the electron beam.

A theory of contamination in electron microscopes by surface diffusion

1978 ◽  
Vol 36 (1) ◽  
pp. 116-117
Author(s):  
J.T. Fourie
Keyword(s):  
Electron Beam ◽  
Surface Diffusion ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Physical Parameters ◽  
Carbon Compounds ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Primary Electrons ◽  
Long Chain

Contamination in electron microscopes can be a serious problem in STEM or in situations where a number of high resolution micrographs are required of the same area in TEM. In modern instruments the environment around the specimen can be made free of the hydrocarbon molecules, which are responsible for contamination, by means of either ultra-high vacuum or cryo-pumping techniques. However, these techniques are not effective against hydrocarbon molecules adsorbed on the specimen surface before or during its introduction into the microscope. The present paper is concerned with a theory of how certain physical parameters can influence the surface diffusion of these adsorbed molecules into the electron beam where they are deposited in the form of long chain carbon compounds by interaction with the primary electrons.

scholarly journals Towards Dry Machining of Titanium-Based Alloys: A New Approach Using an Oxygen-Free Environment

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1161
Author(s):  
Hans Jürgen Maier ◽  
Sebastian Herbst ◽  
Berend Denkena ◽  
Marc-André Dittrich ◽  
Florian Schaper ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Wear Mechanism ◽  
Chip Formation ◽  
Cutting Forces ◽  
High Vacuum ◽  
Argon Atmosphere ◽  
Dry Machining ◽  
New Approach ◽  
Underlying Mechanisms ◽  
Free Environment

In the current study, the potential of dry machining of the titanium alloy Ti-6Al-4V with uncoated tungsten carbide solid endmills was explored. It is demonstrated that tribo-oxidation is the dominant wear mechanism, which can be suppressed by milling in an extreme high vacuum adequate (XHV) environment. The latter was realized by using a silane-doped argon atmosphere. In the XHV environment, titanium adhesion on the tool was substantially less pronounced as compared to reference machining experiments conducted in air. This goes hand in hand with lower cutting forces in the XHV environment and corresponding changes in chip formation. The underlying mechanisms and the ramifications with respect to application of this approach to dry machining of other metals are discussed.

Electron-Beam Surface Treatment of Titanium Alloy Ingots. Part 2

Metallurgist ◽  
2019 ◽  
Vol 63 (3-4) ◽  
pp. 295-299
Author(s):  
S. V. Akhonin ◽  
A. N. Pikulin ◽  
V. V. Klochai ◽  
A. D. Ryabtsev
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Surface Treatment ◽  
Beam Surface

Biocompatible Ceramic-Biopolymer Coatings Obtained by Electrophoretic Deposition on Electron Beam Structured Titanium Alloy Surfaces

2016 ◽  
Vol 879 ◽  
pp. 1552-1557
Author(s):  
C. Ramskogler ◽  
L. Cordero ◽  
Fernando Warchomicka ◽  
A.R. Boccaccini ◽  
Christof Sommitsch
Keyword(s):  
Titanium Alloy ◽  
Surface Modification ◽  
Electron Beam ◽  
Electrophoretic Deposition ◽  
Composite Coatings ◽  
Substrate Surface ◽  
3D Structure ◽  
Titania Nanoparticles ◽  
Structured Surfaces ◽  
Major Interest

An area of major interest in biomedical engineering is currently the development of improved materials for medical implants. Research efforts are being focused on the investigation of surface modification methods for metallic prostheses due to the fundamental bioinert character of these materials and the possible ion release from their surfaces, which could potentially induce the interfacial loosening of devices after implantation. Electron beam (EB) structuring is a novel technique to control the surface topography in metals. Electrophoretic deposition (EPD) offers the feasibility to deposit at room temperature a variety of materials on conductive substrates from colloidal suspensions under electric fields. In this work single layers of chitosan composite coatings containing titania nanoparticles (n-TiO2) were deposit by EPD on electron beam (EB) structured Ti6Al4V titanium alloy. Surface structures were designed following different criteria in order to develop specific topography on the Ti6Al4V substrate. n-TiO2 particles were used as a model particle in order to demonstrate the versatility of the proposed technique for achieving homogenous chitosan based coatings on structured surfaces. A linear relation between EPD time and deposition yield on different patterned Ti6Al4V surfaces was determined under constant voltage conditions, obtaining homogeneous EPD coatings which replicate the 3D structure (pattern) of the substrate surface. The present results show that a combination of both techniques can be considered a promising surface modification approach for metallic implants, which should lead to improved interaction between the implant surface and the biological environment for orthopaedic applications.

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