Total number
Full text
Total number
Full text
Number of local repositories
Full text
0219U100460,
0115U001401
,
Scientific basics development of obtaining and physic-mechanical properties determination of the new class nanostructural superhard nitride coatings based on high-entropy alloys
Voyevodin Viktor M., Доктор фізико-математичних наук
13-02-2019
National Science Center "Kharkiv Institute of Physics and Technology"
The research report contains 54 pages, 15 figures, 15 tables, 40 references. The objects of study are multicomponent high-entropy alloys and coatings. The purpose of the work is to obtain high-entropy cathodes for vacuum-arc deposition of carbide, oxide and nitride coatings. Investigation of physicomechanical properties, structural state, heat resistance of high-entropic coatings. Research methods - measurement of hardness, determination of the level of elasticity and yield boundary by indentation method, determination of friction coefficients by two methods, heat resistance, X-ray diffraction, electron microscopy. It is revealed that solid solutions of WPP based on the BCC lattice are formed at an electron concentration of less than 7.2 electrons / at, and when the electron concentration is above 7.66 electrons / atms, solid solutions are formed on the basis of the fcc lattice. The lattice parameter is determined by the metal, which is more refractory. High-entropy vacuum coatings have a hardness depending on the composition and deposition method from 8 to 12 GPa. At the same time, the type and parameters of the lattice are the same as in cast rapidly cooled alloys. Vacuum-arc high-entropic coatings have a cluster structure with sizes of 2-6 nm, with each cluster differing from each other in composition. For almost all WPPs, an increase in nitrogen pressure in the chamber to 0.6 Pa leads to the formation of textured coatings ([111]), which have a hardness of 50 to 70 GPa. An increase in the negative potential of the substrate during the formation of the coating leads to a decrease in the relative content of the light component (Ti) and nitrogen, as well as an increase in the heavy component (Ta, Hf). In the range of the substrate potential from -50 to -250 V, the single-phase state takes place, but at -50 V it is a virtually non-textured state, and at -250 V, the structure [111] with the highest hardness is formed.
2020-04-02
Updated: 2025-12-06
Saving a scientific data set occurs in two stages:
1.) Creating a data set
Enter the name of the set, a brief description of the set (annotation), and click the “Create set” button. After that, a draft data set will be automatically created, which you can save for further work with the set. The system will redirect you to the “Data set information” page.
2.) Filling in the data
On the “Data set information” page, you need to fill in all the fields related to the data set and upload the files.
Please note! Each file is uploaded separately. This is done to ensure the stable operation of the system.
Once you have filled in the information about the scientific data set and added the necessary files, you can save the draft or send the data to the system.
Please note! Once the data has been sent, you cannot change it.
Drafts are necessary for storing the data set and editing it before sending.
All accounts on the NRA website go through a standard registration procedure and are verified. However, in order to obtain additional features, such as publishing open reviews of academic texts, verification by affiliation is required.
To obtain the status “verified”, you must change your primary email address to a corporate one, which is tied to a scientific or educational institution.
For example: user@ukrintei.ua, user@nas.gov.ua
After confirming your corporate email address, your account will be automatically verified by affiliation.
If your email address is corporate, but your account does not have a verification mark, you need to write to us at the email address NRAT@ukrintei.ua. After verification, we will add your address to the database, and your account will be verified.
After completing the verification procedure for affiliation, you can change the primary email address to a convenient one for you, without losing your status during the current verification.
You only need to verify for affiliation once.
* We use corporate addresses from the Unified State Database on Education and the State Register of Scientific Institutions Supported by the State
To search for news published on the official website of NRАT in the “News” section, you need to enter one word, several words, or an exact phrase in the search field. Different terms are separated by spaces.
The search is performed everywhere – in the title and the news text.
For a more comprehensive result, it is recommended to use word stems (parts of words without endings).
When using multiple words for the search, they are combined using one of the logical methods described below.
By default, the logical connector “and” is used. In this case, search results will include all news releases that contain the specified words, even if they are located separately from each other and are in different parts of the text.
Example: Search phrase: OECD report. Search result: all news containing the words “report” and “OECD” in the text and in the title, both together and separately.
If a phrase or phrase is enclosed in quotation marks (“), the results will include all publications where this exact phrase or phrase is found.
Example: Search phrase: “OECD report.” Search result: all news containing the exact phrase “OECD report.”
If you know the publication date of the news or are interested in a specific time frame in which they were published on the website, you can select such a date or date range in the additional field that looks like a calendar. The date is entered in the format year-month-day and confirmed by clicking on the corresponding date in the calendar dropdown. You can enter a date or choose one by browsing through the calendar by months and years. By default, the interval starts from the oldest date (2018-01-23) and ends with the current date.
You can also use one or more hashtags, which are located under the search field on the right side of the “News” page.
Please note: The search for academic texts is carried out in a separate search window at the following link https://nrat.ukrintei.ua/searchdb.
