ОСНОВНЫЕ ПУБЛИКАЦИИ КОЛЛЕКТИВА ЛАБОРАТОРИИ
2019 год
SEQUENCES OF SUB-MICROSECOND LASER PULSES FOR MATERIAL PROCESSING: MODELING OF COUPLED GAS DYNAMICS AND HEAT TRANSFER
A.V. Gusarov, O.B. Kovalev
Applied Sciences
2019
Multipulse laser processing of materials is promising because of the additional possibilities to control the thickness of the treated and the heat-affected zones and the energy efficiency. To study the physics of mutual interaction of pulses at high repetition rate, a model is proposed where heat transfer in the target and gas-dynamics of vapor and ambient gas are coupled by the gas-dynamic boundary conditions of evaporation/condensation. Numerical calculations are accomplished for a substrate of an austenitic steel subjected to a 300 ns single pulse of CO2 laser and a sequence of the similar pulses with lower intensity and 10 μs inter-pulse separation assuring approximately the same thermal impact on the target. It is revealed that the pulses of the sequence interact due to heat accumulation in the target but they cannot interact through the gas phase. Evaporation is considerably more intensive at the single-pulse processing. The vapor is slightly ionized and absorbs the infrared laser radiation by inverse bremsstrahlung. The estimated absorption coefficient and the optical thickness of the vapor domain are considerably greater for the single-pulse regime. The absorption initiates optical breakdown and the ignition of plasma shielding the target from laser radiation. The multipulse laser processing can be applied to avoid plasma ignition.
POSSIBILITIES OF MANUFACTURING PRODUCTS FROM CERMET COMPOSITIONS USING NANOSCALE POWDERS BY ADDITIVE MANUFACTURING METHODS
S. Grigoriev, T. Tarasova, A. Gusarov, R. Khmyrov, S. Egorov
Materials. – 2019. – Т. 12. – №. 20. – С. 3425.
2019
Complicated wear-resistant parts made by selective laser melting (SLM) of powder material based on compositions of metal and ceramics can be widely used in mining, oil engineering, and other precision engineering industries. Ceramic–metal compositions were made using nanoscale powders by powder metallurgy methods. Optimal regimes were found for the SLM method. Chemical and phase composition, fracture toughness, and wear resistance of the obtained materials were determined. The wear rate of samples from 94 wt% tungsten carbide (WC) and 6 wt% cobalt (Co) was 1.3 times lower than that of a sample from BK6 obtained by the conventional methods. The hardness of obtained samples 2500 HV was 1.6 times higher than that of a sample from BK6 obtained by the traditional method (1550 HV).
RADIATIVE TRANSFER IN POROUS CARBON-FIBER MATERIALS FOR THERMAL PROTECTION SYSTEMS
A.V. Gusarov, E. Poloni, V. Shklover, A. Sologubenko, J. Leuthold, S. White, J. Lawson
International Journal of Heat and Mass Transfer
2019
Highly porous carbon-fiber materials are used in ablative heat shields for atmospheric re-entry. These carbon fiber based materials perform well against heat convection and conduction, and have high radiation absorption. During re-entry, spacecrafts are exposed to shock layer radiation, which provides a considerable share of the heat load faced by their shields. In this work, models for reflectance and heat transfer through FiberForm, a porous carbon-fiber material, are described. The models are based on the multiphase approach and were validated by comparison with experimental data on reflectance and on effective high-temperature thermal conductivity. The morphology of FiberForm was reconstructed from X-ray tomography data and was used as an input for the models. Transmission electron microscopy and diffraction analyses of FiberForm revealed the presence of an amorphous phase and graphite nanocrystalline grains smaller than 10 nm, with no preferential crystallographic orientation. A strong influence of anisotropy in fiber orientation was observed in measured reflectance and has been included in modeling. The porosity and the extinction coefficient were obtained from X-ray tomography images. The radiative transfer modeling indicates that 90% of the incident radiation at wavelengths around 1 μm is absorbed in the 200–300 μm thick outermost surface layer.
A.V. Gusarov
Journal of Heat Transfer
2019
The statistical multiphase approach (MPA) proposed in the first part of this work to evaluate radiative properties of composite materials is applied to porous structures of opaque material and biological tissues. Radiative thermal conductivity is calculated for the bundle of circular rods, packed pebble beds, and metal foams. The results generally agree with the reference calculations by other methods. The small difference can be explained by different approaches to scattering and assumptions about the temperature distribution. Attenuation of light in skin tissues is calculated by the diffusion approximation. The attenuation coefficient generally agrees with the reference Monte Carlo simulation (MC). The difference observed at certain combination of parameters can be due to the assumption of regular arrangement of vessels at the MC simulation.
INVESTIGATION OF THE STRENGTH CHARACTERISTICS OF SAMPLES MADE OF NYLON BY FFF TECHNOLOGY
Skornyakov I. A., Tarasova T. V., Terekhina S. M.
ARPN Journal of Engineering and Applied Sciences. 2019. Vol.14. №13. Р. 2427-2432.
2019
Additive manufacturing of polymer products over the past decade has become widespread in various areas of industry. Using the FFF method, one of the most technologically simple methods of additive manufacturing, it is possible to produce parts from a large number of different materials, including wear-resistant nylon. This article reflects the process of manufacturing samples from nylon using FFF technology with various internal topologies, as well as tensile tests. The analysis of the obtained results is performed and the relationship between the structure of the sample and the limit of its strength is established. The FFF method is promising for developing methods for producing composite materials. The results of this article can be useful in choosing the necessary manufacturing parameters.
Filatova A., Tarasova T., Peretyagin P.
MATEC Web of Conferences 298, 00116 (2019)
2019
Favorable parameters for selective melting methods using electron and laser radiation have been established to obtain the required geometric, physical and mechanical characteristics of thin-walled parts for aviation purposes from H18N9T (analogue AISI 321) and Ti6Al4V alloys. Parts were manufactured and field tests were carried out on the stand. It has been shown that the technological processes developed using the SLM and SEBM methods can be recommended for the manufacture of thin-walled parts working in conditions of rapidly changing deformations.
Filatova A., Tarasova T.
Materials Today: Proceedings. – 2019. – V. 11, Issue P1, – P. 300-304.
2019
Tactics are given for the design and manufacture of individual implants for patients with two-level instability of lumbar vertebral segments L3-L4, L4-L5. Interbody stabilisation was performed by Professor V.V. Dotsenko using implants manufactured by Arcam AB (Sweden) and LTD “CONMET” (Russia). The Laboratory of Innovative Additive Technologies at Moscow State University of Technology STANKIN (LIAT STANKIN) studied the properties of Arcam AB’s Ti6Al4V powder.
Tarasova T. V., Gvozdeva G.O., Ableyeva R. R.
Materials Today: Proceedings. – 2019. – Volume 11, – Issue P1, – P. 305 – 310.
2019
3D laser metal deposition (LMD) based on the laser cladding is an established technique for additive manufacturing tasks. Also
the laser cladding is a well-known technique to produce aluminum matrix composites reinforced by Si particles. High cooling
rates typical for laser treatment enable to eliminate coarse Si particles formation which is a substantial disadvantage of in-situ Al-
Si composites produced by traditional manufacturing processes like casting. The coarse Si particles formation reduces Al-Si
composites mechanical properties. Extremely non-equilibrium solidification conditions typical for micro LMD process allow to
obtain a further structure refinement and its mechanical properties improvement. In this paper the in-situ Al-Si composites
produced by micro LMD process with different parameters sets were investigated by fine structure X-ray analysis. The structure
and phase composition of in-situ Al-Si composites were described. The influence of cladding parameters on Al-Si composites
structure was investigated.
Terekhina, S., Skornyakov, I., Tarasova, T., Egorov, S.
Technologies. – 2019. – Т. 7. – №. 3. – С. 57.
2019
Additive manufacturing of polymer products over the past decade has become widespread in various areas of industry. Using the fused filament fabrication (FFF) method, one of the most technologically simple methods of additive manufacturing, it is possible to produce parts from a large number of different materials, including wear-resistant nylon. The novelty of the work is properties investigation of ±45° filling configuration with different filling degree for nylon, as well as calculating the effect of infill on the strength characteristics, excluding the shell. This article reflects the process of manufacturing samples from nylon using FFF technology with various internal topologies, as well as tensile tests. The analysis of the obtained results is performed and the relationship between the structure of the sample and the limit of its strength is established. To calculate real filling degree and the effect of internal filling on the strength characteristics of the specimen, it is proposed to use a method based on the geometric and mass parameters. The FFF method is promising for developing methods for producing a composite material. The results of this article can be useful in choosing the necessary manufacturing parameters.
Tarasova T., Filatova A.
IOP Conference series: Materials Science and Engineering. – 2019. – 709(2).
2019
Rational selective laser melting modes have been established for the manufacture of parts from domestic powder of steel grade 20H13. The properties of PR20H13 powder have been studied using the methods of granulometric analysis. The physical and mechanical properties of samples manufactured using rational modes of selective melting have been determined.
Terekhina, S., Skornyakov, I., Tarasova, T., Egorov, S.
Technologies. – 2019. – Т. 7. – №. 3. – С. 57.
2019
Additive manufacturing of polymer products over the past decade has become widespread in various areas of industry. Using the fused filament fabrication (FFF) method, one of the most technologically simple methods of additive manufacturing, it is possible to produce parts from a large number of different materials, including wear-resistant nylon. The novelty of the work is properties investigation of ±45° filling configuration with different filling degree for nylon, as well as calculating the effect of infill on the strength characteristics, excluding the shell. This article reflects the process of manufacturing samples from nylon using FFF technology with various internal topologies, as well as tensile tests. The analysis of the obtained results is performed and the relationship between the structure of the sample and the limit of its strength is established. To calculate real filling degree and the effect of internal filling on the strength characteristics of the specimen, it is proposed to use a method based on the geometric and mass parameters. The FFF method is promising for developing methods for producing a composite material. The results of this article can be useful in choosing the necessary manufacturing parameters.
Tarasova T.V., Belashova I.S., Kuzmin S.D., Egorov S.A.
"Materials Science Forum" (издательствао Trans Tech Publications Ltd.). – 2019. – Volume , – Issue, – P. 2427-2432
2019
In this paper effect of a fiber laser on the microstructure and properties of steels 95X18 and 12X18H10T is shown. The regularities of changes in the structure of a laser-treated surface by X-ray diffraction and X-ray microscopic analyzes were studied. The high efficiency of laser heat treatment of steel 95X18 with the subsequent tempering, to improve the tribological properties of the surface layers has been established. For steel 12X18H10T laser shock hardening method (405 HV) is recognized to be effective.