Formation of the structure and properties of Cu-Pd alloys during the A1-B2 phase transformations

2008 ◽  
Vol 106 (4) ◽  
pp. 341-352
Author(s):  
A. Yu. Volkov ◽  
V. A. Kazantsev ◽  
N. I. Kourov ◽  
N. A. Kruglikov
2021 ◽  
Vol 03 (01) ◽  
pp. 79-88
Author(s):  
Davron Rakhmonovich Djuraev ◽  
◽  
Mokhigul Madiyorovna Jamilova ◽  

The article studies the physical properties of rare earth metals, pays special attention to their unique properties, studies the main aspects of the application of rare earth metals in industry. Also, the structure and stability of various forms of sesquioxides of rare earth elements, in particular, europium, as well as the effect of the method of oxide preparation on its structure and properties are considered. The analysis of the ongoing phase transformations of rare earth metals is made. The article emphasizes the use of correct choices to achieve a large technical and economic effect when using rare earth metals in industry. The article is intended for teachers working in the field of physics and chemistry, as well as for students of the specialty "physics and chemistry".


Author(s):  
V.I. Kyrychenko ◽  
V.V. Kyrychenko ◽  
V.P. Nezdorovin ◽  
A.I. Stremetskyi

The article reflects certain applied aspects of a new direction of energy — biosynthetic energy sources, such as bio-oils obtained from technical oils. In particular, there are considered results of the research of the influence of such a characteristic factor of base oils and, first of all, bio-oils as their surface activity on energy efficiency and reliability of operation of friction units lubricated by them under the conditions of the boundary regime of friction. It is proved that the surface activity of oils as an indicator of their functional quality is due to the peculiarities of the structure and properties of their molecules, the energy fields of which evoke certain tribochemical interactions with triboactivated nano-surfaces of friction steels. Separate provisions for evaluating the effect of the tribochemical activity of oils on the process of modifying the steel surfaces of functioning friction units have been formed. The essence of X-ray examination of the influence of lubricating media on the condition of the steel surface by the method of a sliding X-ray beam, analyzing the surface layers with a depth of 0.5–7 mkm. The effect of significant influence of bio-oils obtained from oils on the phase transformations of the structure and properties of the steel surface during tribe tests of samples on friction and wear is revealed. It is established that the effect of obtaining the crystal structure of steel with surface hardening under the deformed layer depends on the tribochemical activity of the proposed three lubricating compositions, which are characterized by the algorithmic growth of such activity. It is proved that the tribochemical activity of bio-oils (in compositions 2 and 3, estimated by the intensity of phase transformations in the surface layers (the effect of Rebinder PO), leads, in turn, to improved friction and wear of lubricated samples compared to the composition 1 low triboactivity. X-structural surfaces analysis of the samples of steel 45 in the initial state and after testing in the media of each of the compositions showed that in the friction processes there is a destruction of the structure of austenite with the release of α-phase (ferrite). It is shown that the intensity of such modification of steel surfaces is progressively amplified in samples lubricated with compositions in accordance with their increasing triboactivity. It was found that with the penetration into the surface layers of steel (from 0.5 to 7 mkm), lubricated with bio-oils of the samples after their tribometer tests, the amount of ferrite increases and the content of austenite decreases. This reduces the deformability of the structure of metal crystals, which leads to the strengthening of its surface under its plasticized layer, and hence the reduction of friction and wear due to the formed intersurface servito-tribopolymer film, resistant to friction. Bibl. 12, Fig. 5, Tab. 3.


2013 ◽  
Vol 203-204 ◽  
pp. 339-342
Author(s):  
Danuta Stróż ◽  
Jakub Palka ◽  
Zdzisław Lekston ◽  
Agniwszka Smołka

Ni-rich alloy (50.8at.%Ni) was plastically deformed by compression combined with reversion oscillating torsion. The compression rate was 0.05 mm/s and the torsion frequency and angle were 1,5Hz and ±3°. After the deformation process the specimens were annealed at 350°C/1h (623K/1h) and 400°C/1h (673K/1h). Their structure and transformation characteristic were studied with the use of TEM, X-ray phase analysis and DSC measurements. TEM observation of specimens after annealing at 350°C/1h (623K/1h) indicate presence of highly deformed B2 phase. In the specimen annealed at 400°C/1h (673K/1h) additionally Ni4Ti3 precipitates and the R-phase in the B2 matrix was found. DSC measurements show that the transformation sequence changes for the deformed and then annealed samples from single step B2  B19’ transformation to the B2  R  B19’ on cooling. Also increase of R-phase transformation temperature TR with the decrease of annealing temperature was observed.


2013 ◽  
Vol 738-739 ◽  
pp. 518-524 ◽  
Author(s):  
Sergey Belyaev ◽  
Maria Drozdova ◽  
Natalia Frolova ◽  
Vitaly Pilyugin ◽  
Natalia Resnina ◽  
...  

Processes, occurring on annealing of TiNi alloy, processed by high pressure torsion (HPT), were the focus of this research. Some peaks of heat release were found on heating the deformed samples up to 550 °C. If the initial structure of the alloy was amorphous (after 3.5 turns of HPT), then structural relaxation, crystallization and grain growth occurred on heating. When alloys had a crystalline structure (after rotation by 15 and 90 degrees), recovery, recrystallization and further grain growth took place on heating. It was observed that the TiNi alloy, subjected to 3.5 turns of HPT and subsequent heating up to 550 °C, underwent unusual kinetics of martensitic transformations. The austenite B2 phase transformed to the martensite B19' phase in two ways: B2→R→B19' and B2→ B19'.


2020 ◽  
Vol 774 ◽  
pp. 138891 ◽  
Author(s):  
Vajinder Singh ◽  
Chandan Mondal ◽  
Rajdeep Sarkar ◽  
P.P. Bhattacharjee ◽  
P. Ghosal

2010 ◽  
Vol 667-669 ◽  
pp. 985-990 ◽  
Author(s):  
R.I. Babicheva ◽  
I.Z. Sharipov ◽  
K.J. Mulyukov

The effect of thermal cycling of the Ti - 49.8 at. % Ni alloy deformed by rolling at 500 оС on dilatation of the material was investigated. It was shown that R → B2 and B19' → B2 phase transformations take place during heating due to retaining of R-phase at the lowest temperature of cycling. The evolution and subsequent stabilization of two-way shape memory effect (TWSME) upon thermal cycling are caused by decreasing of the residual B19'- martensitic phase formed during rolling. It was revealed that recoverable strain of the alloy doesn’t exceed 0.8 % even after forty cycles.


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