Role of the phase composition of tungsten containing hard alloys in the formation of a layer of titanium carbide in gas titanizing

1989 ◽  
Vol 28 (7) ◽  
pp. 574-578
Author(s):  
B. V. Zakharov ◽  
A. N. Minkevich ◽  
D. V. Pikunov ◽  
�. R. Ton� ◽  
E. D. Argasova
Author(s):  
A. V. Krokhalev ◽  
V. O. Kharlamov ◽  
E. A. Ivanenko ◽  
D. R. Chernikov ◽  
S. V. Kuz’min ◽  
...  

The principal features of the mechanism of formation of coatings from hard alloys during their production by explosive pressing of mixtures of CrC and Ti powders on metal substrates are described. The phase composition and structure of coatings deposited using loading by a plane normally incident detonation wave and sliding loading are considered.


Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 29-33
Author(s):  
Mariusz Hasiak

Abstract The microstructure and magnetic properties of nanocomposite hard magnetic Nd-Fe-B-(Re, Ti) materials with different Nd and Fe contents are studied. The role of Re and Ti addition in phase composition and volume fraction of the Nd-Fe-B phase is determined. All samples are annealed at the same temperature of 993 K for 10 min. Mössbauer spectroscopy shows that the addition of 4 at.% of Re to the Nd8Fe78B14 alloy leads to creation of an ineligible amount of the magnetically hard Nd2Fe14B phase. Moreover, the microstructure and magnetic characteristics recorded in a wide range of temperatures for the Nd8Fe79−xB13Mx (x = 4; M = Re or Ti) alloys are also analyzed.


2000 ◽  
Vol 36 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Yu. V. Levinskii ◽  
A. P. Petrov
Keyword(s):  

2019 ◽  
Vol 89 (12) ◽  
pp. 1923
Author(s):  
М.Н. Дроздов ◽  
Е.В. Демидов ◽  
Ю.Н. Дроздов ◽  
С.А. Краев ◽  
В.И. Шашкин ◽  
...  

The formation of ohmic Au/Mo/Ti contacts to epitaxial p-type diamond films is studied. The effect of annealing on the electrical and structural properties of contacts has been investigated. It was shown that during rapid thermal annealing, the outer layer of gold protects the contact system from oxidation up to a temperature of 850°C, unlike the simplified Au/Ti system, which is more common in modern works. In Au/Ti structures without a Mo layer after high-temperature annealing, effective diffusion of titanium into the gold layer occurs, which reduces its protective properties and accelerates the diffusion of oxygen to the boundary with the diamond. Oxidation of the Ti/C contact region blocks the formation of a conductive layer of titanium carbide with high adhesion at the border with diamond. The role of various factors in reducing the contact resistance is compared: annealing for the formation of titanium carbide, heavy doping of diamond with boron atoms, and crystalline perfection of epitaxial diamond substrates. For doped epitaxial films grown on single-sector quality substrates, non-annealed ohmic contacts with a record contact resistance of 4•10<-7> Ω•cm<2> were obtained.


2021 ◽  
Vol 47 (1) ◽  
pp. 56-61
Author(s):  
N. D. Yatsenko ◽  
N. A. Vil’bitskaya ◽  
A. I. Yatsenko

2020 ◽  
Vol 992 ◽  
pp. 487-492
Author(s):  
V.O. Kharlamov ◽  
Aleksandr Vasilevich Krokhalev ◽  
S.V. Kuz’min ◽  
V.I. Lysak

The Article presents the findings of the studies of the microstructure, chemical and phase composition of the Cr3C2-Ti system alloys obtained by the explosion. Scanning electron microscopy, energy dispersive and x-ray diffraction analyses were used. The program Thermo-Calc software was used to calculate the equilibrium phases. The phase composition of the compact was shown to fully correspond to that of the initial powder mixture during explosive pressing in the modes of heating from 300 ̊С to 600 ̊С. When heated above 600 ̊С, the chemical interaction of the initial components begins with the formation of new boundary phases. Meanwhile, there is a change in the sample destruction nature and a significant increase in hardness, which points to the hard alloy consolidation. The increase in the powder mixture heating in shock waves to 1000 ̊С leads to intensive macrochemical interaction of the powder mixture components and to formation of an equilibrium phase composition. The established temperature limits determine the most appropriate parameters of shock-wave loading when producing hard alloys by explosive pressing.


2019 ◽  
Vol 974 ◽  
pp. 195-200
Author(s):  
Yury R. Krivoborodov ◽  
Svetlana V. Samchenko

The article presents the results of a study of the effect of synthesized microdisperse additives of crystalline hydrates based on calcium sulfoaluminates on the properties of cement stone. The effectiveness of the use of a rotary pulsation apparatus (RPA) to obtain microdispersed additives is identified. The possibility of accelerating the hardening of cement stone by entering microdispersed additives into its composition is shown. It has been established that in the presence of microdispersed additives of crystalline hydrates in the cement stone, the phase composition of hydrate tumors changes, the amount of calcium hydrosilicates and ettringite increases, the porosity decreases and the strength of the cement stone increases. This provision is confirmed by the increase in the degree of cement hydration, the amount of bound water in all periods of hardening of the stone. It is proposed to use microdisperse additives, which play the role of primers for the crystallization of ettringite and calcium hydrosilicates, to increase the strength of cement stone in the early stages of hardening.


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