Structure and Properties of Leaded Tin Bronze under Different Crystallization Conditions

2013 ◽  
Vol 872 ◽  
pp. 89-93 ◽  
Author(s):  
Nikita Martyushev ◽  
Ilya V. Semenkov ◽  
Yuriy N. Petrenko
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Cooling Rate ◽  
Structure And Properties ◽  
Cooling Rates ◽  
Tin Bronze ◽  
Microstructure Parameters ◽  
Influence Of Crystallization ◽  
Crystallization Conditions ◽  
High Cooling Rates

The influence of crystallization conditions of leaded tin bronze on the obtained microstructure parameters is examined in the paper. Modification of crystallization conditions was realised by varying the cooling rate of the melt with preheating of the casting molds. Quantitative regularities of the influence of the cooling rate of bronze on its phase composition are presented. Data on mechanical properties of the material under investigation are also reported in the paper. It is demonstrated that high cooling rates (casting into mold at ambient temperature) enable obtaining higher mechanical properties in comparison with low cooling rates (casting into mold heated up to 800 °С).

Regularities of the formation of the phase composition, structure and properties of the БрНХК 2.5-0.7-0.6 alloy during thermal and aerothermoacoustic treatments

2021 ◽  
pp. 71-75
Author(s):  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Aging Treatment ◽  
Structure And Properties ◽  
Additional Increase ◽  
Composition Structure ◽  
Aerothermoacoustic Treatment

The influence of thermal and aerothermoacoustic treatments on the structure and mechanical properties of БрНХК bronze is considered. An increase in the strength and elasticity of the alloy is established by optimizing the thermal and aerothermoacoustic modes. The influence of the pre-aging treatment, the aging and aerothermoacoustic modes on the structure, the possibility of an additional increase in the mechanical properties of wire from БрНХК after aerothermoacoustic treatment are shown. Keywords: bronze, heat treatment, aerothermoacoustic treatment, microstructure, mechanical properties. [email protected]

Microstructure Characterization of Ni-75 at.% Al Raney Type Alloy as a Result of Cooling Rate and Chromium Doping

MRS Advances ◽  
2019 ◽  
Vol 4 (25-26) ◽  
pp. 1441-1447
Author(s):  
Naveed Hussain ◽  
Andrew M Mullis ◽  
Jennifer S Forrester
Keyword(s):  
Catalytic Activity ◽  
Phase Composition ◽  
Cooling Rate ◽  
Rietveld Refinement ◽  
Volume Fraction ◽  
Size Fraction ◽  
Standard Size ◽  
Globular Structure ◽  
Cooling Rates ◽  
Size Fractions

ABSTRACTThe effect of cooling rate on the phase composition of gas atomized Raney type catalysts was studied using the Ni-75 at.% Al composition. The resulting particles were sieved into 3 standard size fractions and analysed using XRD with Rietveld refinement: as expected the three phases, Al₃Ni₂, Al₃Ni, and Al-Al₃Ni eutectic were identified. Differing phase compositions in the 3 size ranges were identified offering a possible explanation for varying catalytic activity with cooling rate, the higher cooling rates experienced by the smaller droplets allow less time for the peritectic conversion of Al₃Ni₂ to Al₃Ni to proceed. This in turn results in a more Al-rich residual liquid, increasing the volume fraction of eutectic. This was further confirmed when analysing the microstructure using SEM backscatter imaging. Al₃Ni₂ was found to be encased in a shell of Al₃Ni characteristic of peritectic reactions. The remainder of the alloy was found to consist of Al-Al₃Ni eutectic. The SEM backscatter imaging also indicated that the larger particles displayed and a more globular structure than smaller particles. Similar Raney type Ni-75 at.% Al doped with 1.5 at.% Cr were synthesised using the same method and sieved into the same 3 standard size fractions. It was found that the Cr doped alloys exhibited a more dendritic character than the undoped samples in the corresponding size fraction, although the material still displayed an increasingly dendritic character with increasing cooling rate. The phase composition found by Rietveld refinement also followed a similar trend to the undoped samples with decreasing amounts of Al₃Ni formed at the higher cooling rates. However, significant amounts of an additional phase, Al₁₃Cr₂, were also observed. Rietveld refinement found that a larger amount of Al₁₃Cr₂ was present than could be accounted for by the addition of 1.5 at.% Cr . This can be explained by the substitution of Ni onto the Cr lattice, as confirmed by Rietveld refinement. Al₁₃Cr₂ was found to be located mostly at the boundary of the Al₃Ni and Al-Al₃Ni eutectic phases during elemental mapping and quantitative image analysis of backscattered electron micrographs. This indicates that precipitation of Al₁₃Cr₂ is towards the end of the solidification process. The relatively large amounts of the Al-rich Al₁₃Cr₂ may explain the enhanced catalytic activity observed following leaching of Cr-doped Raney catalysts.

scholarly journals Experimental Investigation of In-Plane Shear Behaviour of Thermoplastic Fibre-Reinforced Composites under Thermoforming Process Conditions

2021 ◽  
Vol 5 (9) ◽  
pp. 248
Author(s):  
Nikita Pyatov ◽  
Harish Karthi Natarajan ◽  
Tim A. Osswald
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Sheet Material ◽  
Matrix Material ◽  
Shear Behaviour ◽  
Temperature Cycle ◽  
Process Conditions ◽  
Cooling Rates ◽  
Dsc Measurements ◽  
Thermoforming Process

In order to meet environmental regulations and achieve resource efficiency in the series production of vehicles, recyclable polymer composites with a high strength-to-weight ratio are increasingly being used as materials for structural components. Particularly with thermoplastic fibre-reinforced polymers or organo-sheets, the advantage lies in the tailored mechanical properties of the final component by adapting the orientation of fibres based on the direction of loads. These components produced by thermoforming organo-sheets also offer a cost benefit and short cycle times. During the thermoforming process, the shear behaviour of the organo-sheet is the most dominant and determines the mechanical properties and quality of the resulting component. However, the current standard for characterising the shear behaviour of organo-sheets does not consider the strain and cooling rates inherent in the thermoforming process. This research investigates the influence of thermoforming process parameters on the shear behaviour of organo-sheets with a new methodology combining DSC and DMA experiments. During the thermoforming process, the transition of the matrix material from a molten state to a solid state is dictated by the crystallisation kinetics and their dependence on heating and cooling rates. Thus, non-isothermal DSC scans, which correspond to a temperature cycle in a thermoforming process, are used in the DSC experiments to establish the relationship between the recrystallisation temperature of the organo-sheet material and the cooling/heating rates in the thermoforming process. In order to achieve thermoforming-process-relevant cooling rates, fast scanning calorimetry (Flash DSC) is used in addition to conventional DSC measurements. DMA experiments carried out with 45° fibre orientation show that the recrystallisation temperature consequently influences the shear storage modulus of the organo-sheet. The results from DSC measurements show a shift of recrystallisation temperatures to lower temperatures as the cooling rate increases. The combined analysis of results from the DSC and DMA experiments supports the findings and shows the influence of the process temperature, cooling rate and strain rate on the recrystallisation temperature and, in turn, the shear behaviour of organo-sheets. Thus, a recommendation for establishing a new standard for characterising the shear behaviour of organo-sheets is made.

scholarly journals FORMATION OF THE STRUCTURE AND PROPERTIES OF THE ZONE OF ALLOYING UNDER PLASMA-POWDER SURFACING OF COATS TYPE EuTroLoy 16006.04

2017 ◽  
pp. 54-57
Author(s):  
F. I. Panteleenko ◽  
V. V. Zakharenko ◽  
M. V. Spetsian
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Surface Coating ◽  
Experimental Studies ◽  
Structure And Properties

The paper presents the results of experimental studies on the surface coating of powder EuTroLoy 16006.04 with the help of plasma-powder overlaying. Analysis of the macro-structure made it possible to establish a partial absence of pores, fusions and cracks between the sub-spoon and the deposited layer. Differences in the phase composition and in the mechanical properties of the coatings were established. In places of application of plasma-powder overlaying an increase in hardness has been revealed. 

scholarly journals The Influence of Thermal Residual Stresses on Mechanical Properties of Silicon Nitride-Based Composites

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1092
Author(s):  
Aleksandra Dubiel ◽  
Grzegorz Grabowski ◽  
Marcin Goły ◽  
Stanisław Skrzypek
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Phase Composition ◽  
Silicon Nitride ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Thermal Residual Stresses ◽  
Microstructure Parameters ◽  
Xrd Method

In this work, two kinds of silicon nitride-based composites, namely, those with titanium nitride or silicon carbide additives, were sintered using the hot pressing technique (HP). The phase composition, microstructure, and mechanical and elastic properties of the materials were characterized. Three-dimensional geometric models of the composites were created on the basis of microstructure parameters. Using these models, bulk residual thermal stresses were calculated by the finite element method (FEM). Surface stresses were determined using the XRD method of sin2ψ.

Effect of Ultra-Fast Cooling Rate on the Microstructure and Mechanical Properties of High Strength Cold-Rolled Sheet under Continuous Annealing

2018 ◽  
Vol 913 ◽  
pp. 311-316
Author(s):  
Kai Zhang ◽  
Ren Bo Song ◽  
Feng Gao ◽  
Wen Jie Niu ◽  
Chi Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Cooling Rate ◽  
High Strength ◽  
Rolled Sheet ◽  
Cooling Rates ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Cold Rolled ◽  
Fast Cooling

The effect of different fast cooling rates on the microstructure and mechanical properties of the V and Ti microalloyed high strength cold-rolled sheet was studied under laboratory conditions. Five different fast cooling rates were set up as 20°C/s, 50°C/s, 200°C/s, 500°C/s and 1000°C/s, respectively. Optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the microstructure, and the mechanical properties were also tested. The results showed that with the increase of fast cooling rate from 20°C/s to 1000°C/s, the grains of martensite and ferrite were finer, and the average grain size of both martensite and ferrite decreased from 7.7μm to 3.9μm. The proportion of ferrite in the two phases decreased while that of the martensite increased from 25.7% to 62.1%. The morphology of martensite tended to be lath, and the density of dislocation in the ferrite grains nearby the martensite gradually increased. With cooling rate rising from 20°C/s to 1000°C/s, the yield strength of the experimental steel increased from 381MPa to 1074MPa, and the tensile strength increased from 887MPa to 1199MPa. And the elongation decreased from 14.2% to 7.2%, and the product of strength and elongation decreased from 12.6GPa·% to 8.6GPa·%.

Structure and Properties of Laser-Welded Joints from High-Strength Steels

2014 ◽  
Vol 682 ◽  
pp. 240-245 ◽  
Author(s):  
O. Berdnikova ◽  
V. Sydorets ◽  
T. Alekseienko
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Phase Composition ◽  
Welded Joints ◽  
High Strength Steel ◽  
Crack Nucleation ◽  
High Strength Steels ◽  
High Strength ◽  
Structure And Properties ◽  
Welding Zone

Presented are the results of investigations of peculiarities of structure formation and phase composition in a metal of laser-welded joints from high-strength steel 14KhGN2MDAFB. The analytical evaluations of strengthening along a welding zone and crack nucleation stresses in the places of stress concentrators determined using the experimental data that a structure being formed provides for uniform level of mechanical properties and crack resistance of the welded joints.

scholarly journals Effect of cooling rates after annealing on the microstructure and properties of 1000MPa grade automobile steel for cold forming

2021 ◽  
Author(s):  
Ruifeng Dong ◽  
Qingbo Zhao ◽  
Xiaohong Bi ◽  
Deng Xiangtao ◽  
Wentian Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cooling Rate ◽  
Testing Machine ◽  
Phase Region ◽  
Two Phase ◽  
Tensile Testing Machine ◽  
Cooling Rates ◽  
Cold Forming ◽  
Automobile Steel

Abstract The effects of different cooling rates ( 0.05℃/s, 0.1℃/s, and 0.2℃/s ) on the microstructure and mechanical properties of 1000 MPa grade automobile steel for cold forming after two-phase annealing were studied. The microstructure of the experimental steel was observed by SEM and TEM, and its mechanical properties were tested by a universal tensile testing machine. The results showed that by increasing the cooling rate of two-phase annealing, more massive retained austenite, more uniform and fine ferrite, better elongation and higher ultimate tensile strength of steel can be obtained, so as to obtain better production of tensile strength and total elongation ( product of tensile strength and elongation, PSE ). The final result shows that after the test steel is quenched at 800℃ + 10 minutes and annealed in the two-phase region at 690℃ + 10 minutes, the faster the cooling rate, the better the mechanical properties. The mechanical properties of the steel plate are the best when the cooling rate reaches 0.2℃/s, and PSE can reach 27.44 GPa·%.

Improvement of Mechanical Properties of Fe-Cr-Mo-[Cu-Ni]-C Sintered Sintered Steels by Sinter Hardening

2011 ◽  
Vol 672 ◽  
pp. 31-38 ◽  
Author(s):  
Eva Dudrová ◽  
Marco Actis Grande ◽  
Mario Rosso ◽  
Margita Kabátová ◽  
Róbert Bidulský ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Chemical Composition ◽  
Cooling Rate ◽  
Impact Energy ◽  
Vacuum Sintering ◽  
Cooling Rates ◽  
Sintered Steels ◽  
Conventional Sintering

The effect of high temperature sintering and high cooling rate on shifting the microstructural composition to the favourably of martensite-bainite structures and thus effective improvement of mechanical properties of sintered steels based on Astaloy CrL powder with an addition of 1 and 2% Cu or 50% Distaloy AB powder and 0.65% C was investigated. All the systems were processed by both sinter-hardening and conventional sintering. The vacuum sintering at high-temperature of 1240 0C and at common temperature of 1180 0C were integrated with high (6 0C/s), medium (3 0C/s) and slow (0.1 0C/s) cooling rates; conventional sintering at 1180 0C with cooling rate of ~0.17 0C/s was carried out in a N2+10%H2 atmosphere. In dependence on chemical composition, the yield and tensile strengths of 890-1150 MPa and 913-1230 MPa respectively and impact energy of 10-15 J were achieved by sinter-hardening. The yield and tensile strengths are approximately double than those resulting from conventional sintering.

Predicting the effect of cooling rate on the mechanical properties of glass fiber–polypropylene composites using artificial neural networks

2018 ◽  
Vol 32 (9) ◽  
pp. 1268-1281 ◽  
Author(s):  
Mohammed S Kabbani ◽  
Hany A El Kadi
Keyword(s):  
Mechanical Properties ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Glass Fiber ◽  
Cooling Rate ◽  
Cooling Rates ◽  
Polypropylene Composites ◽  
Unidirectional Glass ◽  
Static Tensile ◽  
Artificial Neural

Properties of thermoplastic-based composites are affected by their processing conditions, and understanding their behavior under these different conditions is of most importance. The current study aims to predict the static tensile behavior of unidirectional glass fiber–polypropylene composite materials processed under different cooling rates using artificial neural networks (ANNs). Stress–strain relations for the material processed under various cooling rates were predicted using ANN. For all the cases investigated, the modulus of elasticity was predicted with a minimum accuracy of 97%, while the ultimate strain was predicted, in most cases, with a minimum accuracy of 90%. These predictions indicate that ANN can be successfully used to predict the mechanical properties of unidirectional composites manufactured under different cooling rates. This method allows users to predict the behavior of the material under cooling rate conditions for which no experimental data are available.

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