scholarly journals Directed laser processing of compacted powder mixtures Al2O3-TiO2-Y2O3

2013 ◽  
Vol 45 (3) ◽  
pp. 247-259 ◽  
Author(s):  
M. Vlasova ◽  
M. Kakazey ◽  
Márquez Aguilar ◽  
E.A. Juarez-Arellano ◽  
Guardian Tapia ◽  
...  
Keyword(s):  
Laser Processing ◽  
Al2o3 Content ◽  
Heating Zone ◽  
Eutectic Alloys ◽  
Directed Movement ◽  
Powder Mixtures ◽  
Irradiation Zone ◽  
Temperature Heating ◽  
High Temperature Heating ◽  
Sintered Layer

The phase formation, microstructure and surface texture of laser treated ternary powder mixtures of Al2O3-TiO2-Y2O3 had been studied. Rapid high temperature heating and subsequent rapid cooling due to the directed movement of the laser beam forms concave ceramic tracks. Phase composition and microstructure of the tracks depends on the Al2O3 content and the TiO2/Y2O3 ratio of the initial mixtures. The main phases observed are Y3Al5O12, Y2Ti2O7, Al2O3 and Al2TiO5. Due to the temperature gradient in the heating zone, complex layered structures are formed. The tracks consist of three main layers: a thin surface layer, a layer of crystallization products of eutectic alloys, and a lower sintered layer. The thickness of the crystallization layer and the shrinkage of the irradiation zone depend on the amount of Y3Al5O12 and Al2O3 crystallized from the melt.

FEATURES OF STRUCTURE FORMATION IN NI-C, AL-C AND NI-AL-C SYSTEMS UNDER HIGH-TEMPERATURE HEATING

2021 ◽  
Vol 21 ◽  
pp. 3-8
Author(s):  
Sergey Vadchenko ◽  
◽  
Alexandr Shchukin ◽  
Alexander Sytschev ◽  
Olga Boyarchenko
Keyword(s):  
High Temperature ◽  
Spherical Shape ◽  
Temperature Treatment ◽  
Spherical Particles ◽  
High Temperature Treatment ◽  
Powder Mixtures ◽  
Graphite Coating ◽  
Temperature Heating ◽  
High Temperature Heating ◽  
Intermetallic Compound Nial

The high-temperature treatment of powder mixtures of Ni-C, Al-C and Ni-Al-C (5% wt C (soot)) has been carried out up to the melting temperature of the metals. It was found that melt particles coagulate with the formation of spherical particles of Ni, Al, and the intermetallic compound NiAl, respectively. Ni particles are characterized by the almost perfect spherical shape and a multilayer graphite coating. NiAl particles have a thin graphene (graphite) coating.

scholarly journals Processes connected with local laser heating of TiB2 armor ceramics

2019 ◽  
Vol 51 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Marina Vlasova ◽  
Mykola Kakazey ◽  
Pedro Aguilar ◽  
Rene Tapia ◽  
Adalberto Hernandez ◽  
...  
Keyword(s):  
Titanium Oxides ◽  
X Ray Diffraction ◽  
Irradiation Zone ◽  
X Ray ◽  
Pulsed Mode ◽  
Laser Induced Breakdown ◽  
Armor Ceramics ◽  
Temperature Heating ◽  
High Temperature Heating ◽  
Dense Films

The process of high-temperature heating of TiB2 armor ceramics in air in a continuous and pulsed mode of laser irradiation has been studied by the X-ray diffraction and SEM methods. It has been established that, in the irradiation zone, the temperature increases up to 3000 ?C and over, resulting in the decomposition of TiB2 and appearance of ablation products, which, in passage of air, oxidize and form dense films (in the pulsed mode) or ?reticulated? films (in the CW mode) consisting of boron and titanium oxides. The mechanism of laser-induced breakdown of TiB2 ceramics is similar to the mechanism of ballistic destruction.

Features of laser drilling of porous aluminosilicate ceramics

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3045-3054
Author(s):  
P.A. Márquez Aguilar ◽  
M. Vlasova ◽  
E. Moreno Bernal ◽  
M. Kakazey ◽  
R. Guardian Tapia ◽  
...  
Keyword(s):  
Laser Heating ◽  
Glass Phase ◽  
Porous Ceramics ◽  
Heating Zone ◽  
Dynamic Impact ◽  
Laser Perforation ◽  
Temperature Heating ◽  
Thermo Physical Properties ◽  
Highly Porous ◽  
High Temperature Heating

AbstractStudies have shown that local laser heating/“drilling” of composite large-porous ceramics consisting of aluminosilicates and glass phase is based on melting and ablation processes that lead to the formation of holes in a porous specimen. The interaction of the components of the composite in the high-temperature heating zone is accompanied by the formation of glass-phase melt of new composition. The advance of the melt deep into the sample along channel-like pores of the main ceramic material depends on the viscosity of the melt (i.e., the irradiation mode) and the cooling rate of the melt (i.e., the thermo-physical properties of the ceramics and glass phase). The development of gas-dynamic impact in the laser heating zone leads not only to the ejection of a part of the melt from the channel, but also to the compaction of the ceramics adjacent to the walls of the vitrified channel. These effects depend heavily on the ceramic-to-glass phase ratio and the porosity of the initial ceramic. It has been established that “laser perforation” of highly porous aluminosilicate ceramics leads to the hardening of the coarse-porous ceramics due to the formation of holes with strong walls, consisting of layers of the glass phase and compacted ceramics in the sample.

Modeling the High-Temperature Heating of Scrap Metals

Vestnik MEI ◽  
2019 ◽  
Vol 6 ◽  
pp. 58-63
Author(s):  
Konstantin V. Strogonov ◽  
◽  
Andrey A. Chaymelov ◽  
Keyword(s):  
High Temperature ◽  
Scrap Metals ◽  
Temperature Heating ◽  
High Temperature Heating

Can microorganisms survive high-temperature heating during the interplanetary transfer by meteorites?

BIOPHYSICS ◽  
2007 ◽  
Vol 52 (6) ◽  
pp. 640-644 ◽  
Author(s):  
A. K. Pavlov ◽  
V. N. Shelegedin ◽  
V. T. Kogan ◽  
A. A. Pavlov ◽  
M. A. Vdovina ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Heating ◽  
High Temperature Heating

Phase composition of steel 0Kh21N6B after high-temperature heating and tempering

1969 ◽  
Vol 11 (4) ◽  
pp. 331-332
Author(s):  
�. G. Fel'dgandler ◽  
E. N. Kareva ◽  
E. F. Yakovleva
Keyword(s):  
Phase Composition ◽  
High Temperature ◽  
Temperature Heating ◽  
High Temperature Heating

Relieving of Residual Stresses in Metal Workpieces at High and Low Temperatures

2021 ◽  
Vol 887 ◽  
pp. 651-656
Author(s):  
Marina V. Polonik
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Residual Stresses ◽  
Low Temperatures ◽  
Creep Properties ◽  
Processing Modes ◽  
Properties Of Materials ◽  
High And Low Temperatures ◽  
Temperature Heating ◽  
High Temperature Heating

On the basis of previously accumulated irreversible deformations, and, consequently, residual stresses, the process of removing residual stresses in metal workpieces under the action of low and high temperatures is simulated. Boundary value problems are solved and here are described regularities that are responsible for removing residual stresses for processing modes: high-temperature heating - cooling, high-temperature heating - holding - cooling, low-temperature heating - holding - cooling. The holding stage is modeled, taking into account the creep properties of materials under Norton creep conditions. According to the dependences of the obtained exact solutions, it is shown that it is the holding process that leads to the relaxation of residual stresses.

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