Force of interphase interaction in theory of elastic mixtures

1982 ◽  
Vol 18 (5) ◽  
pp. 412-417
Author(s):  
L. P. Khoroshun
Author(s):  
A. O. Nagorniy

For many industries, further progress is possible provided that more efficient refractories of new types are created. The refractory concretes bonded by calcium aluminate phosphate binders in comparison with conventional refractories continue to gain in popularity because of the following advantages: quick installation and low construction costs; reduced and simplified furnace maintenance; good thermal-shock resistance; monolithic (no joints); linings of the units done need not be cured to develop initial strength. The longevity of refractory is essentially increasing provided structure is forming under conditions of the service site. That is why developing of new refractory materials must be carried out by means of its structure design. These principles have been realizing in the refractory concretes technology under the limited conditions of refractory lining installation and industrial unit final heat up. The present paper identifies the phosphate phases responsible for developing mechanical-strength properties of high alumina concretes bonded with calcium aluminate phosphate binders. It sets out the colloid and crystalline phases resulted from interphase interaction that provides the basis for calcium aluminate phosphate binders (suspensions) useful to the refractory industry. The concretes obtained retain their volume integrity after 30 cycles of heating and cooling; can be used for refractory applications > 1700 °С; exhibit sufficient strength of lining 40 MPa.


2020 ◽  
Vol 5 ◽  
pp. 75-81
Author(s):  
D.V. Sidorov ◽  
◽  
V.M. Serpova ◽  
A.V. Zavodov ◽  
A.A. Shavnev ◽  
...  

Interaction of the Ti-C with titanium alloys of a + β and pseudo a classes and formation of the reaction layer at the interface have been investigated. We used titanium a + b alloys VT6 (Ti-Al-V) and VT8 (Ti-Al-Mo-Si) as well as pseudo a alloy VT20 (Ti-Al-Zr-Mo-V). The structure and composition of the interfaces were investigated by means of TEM in the scanning beam mode and energy dispersive spectroscopy. It is ascertained that already at the stage of production of the samples by thermal diffusion joining, interphase chemical interaction and formation of the reaction layers occurred. The reaction layer consists of distinct regions of small crystals (nanocrystals TiC of 10-50 nm in size) and large grains of Ti8C5 of 100-500 nm in size. Most of the reaction layer consists of large grains ofTi8C5. It was found that the average thickness of the reaction layer varies depending on the Ti alloy type and is ~0.89 μm (VT6 alloy), ~0.97 μm (VT8 alloy), and ~0.51 μm (VT20 alloy). Additional heat treatment of the samples leads to increasing the thickness of the reaction layer in all Ti-C/Ti alloy systems due to the growth of large grains of titanium carbide.


2018 ◽  
Vol 45 (3) ◽  
pp. 79-86 ◽  
Author(s):  
V.A. Zhorin ◽  
M.R. Kiselev

Mixtures of polyethylene and 80% germanium dioxide, magnesium, magnesium oxide, and sodium chloride were subjected to plastic deformation under a pressure of 0.5–4.0 GPa, and were then investigated by differential scanning calorimetry. The enthalpy of melting of the polymer in certain mixtures reached 300 J/g. On thermograms of deformed mixtures, exothermic processes were observed. The observed thermal effects are possibly due to interphase interaction at the phase boundary.


2014 ◽  
Vol 41 (3) ◽  
pp. 33-36
Author(s):  
M.A. Poldushov ◽  
A.V. Polyanin ◽  
V.A. Moskalev ◽  
E.E. Potapov ◽  
Sh. Prekop ◽  
...  

2018 ◽  
Vol 760 ◽  
pp. 225-230
Author(s):  
Jan Trejbal ◽  
Zdeněk Prošek ◽  
Josef Fládr ◽  
Pavel Tesárek

The presented work focuses on plasma modifications of polymer and glass micro-fibers (having 32 and 14 μm in the diameter, respectively) used as randomly distributed and oriented reinforcement of concrete composites. Fiber surfaces were modified by means of the low-pressure coupled cold oxygen plasma in order to attain a strong adhesion with the cement matrix. From the perspective of micro scale, an impact of modifications on both the physical and the chemical surface changes of treated fibers was examined using: (i) a wettability measurements – an evaluation of an interphase interaction between demineralized water and fibers and (ii) the SEM microscopy – an assessment of a surface morphology. From the perspective of macro scale, the interaction between the two materials was examined by destructive four-point bending tests of the cement paste containing both the reference and treated fibers (specimens having dimensions equal to 40×40×160 mm, water to cement ration 0.4) were done. It was shown that the wettability of modified fibers was increased by approx. 10 % and 70 % in the case of glass and polymer fibers, respectively. The SEM morphology analysis revealed fine roughening of treated fibers, if compared to the reference ones. The mechanical testing pointed out on a toughness increase in the post-cracking response of loaded specimens.


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