scholarly journals The Effect of Cooling Rate on Properties of Intermetallic Phase in a Complex Al-Si Alloy

2016 ◽  
Vol 16 (3) ◽  
pp. 125-128 ◽  
Author(s):  
M. Tupaj ◽  
A.W. Orłowicz ◽  
M. Mróz ◽  
A. Trytek ◽  
O. Markowska
Keyword(s):  
Elastic Modulus ◽  
Cooling Rate ◽  
Material Properties ◽  
Intermetallic Phase ◽  
Indentation Hardness ◽  
Instrumented Indentation ◽  
Silicon Alloy ◽  
The Matrix ◽  
Crystallisation Process ◽  
Technological Options

Abstract The cooling rate is one of the main tools available to the process engineer by means of which it is possible to influence the crystallisation process. Imposing a desired microstructure on a casting as early as in the casting solidification phase widens significantly the scope of technological options at disposal in the process of aluminium-silicon alloy parts design and application. By changing the cooling rate it is possible to influence the course of the crystallisation process and thus also the material properties of individual microstructure components. In the study reported in this paper it has been found that the increase of cooling rate within the range of solidification temperatures of a complex aluminium-silicon alloy resulted in a decrease of values of the instrumented indentation hardness (HIT) and the instrumented indentation elastic modulus (EIT) characterising the intermetallic phase occurring in the form of polygons, rich in aluminium, iron, silicon, manganese, and chromium, containing also copper, nickel, and vanadium. Increased cooling rate resulted in supersaturation of the matrix with alloying elements.

Study on the Effects of the Nonhomogeneous Material Properties on the Structure Strength of the Induction Quenched Crankshaft

2014 ◽  
Vol 703 ◽  
pp. 400-405
Author(s):  
Ji Shan Li ◽  
Ri Dong Liao ◽  
Guo Hua Chen
Keyword(s):  
Elastic Modulus ◽  
Material Properties ◽  
Fem Model ◽  
Explosion Pressure ◽  
Nonhomogeneous Material ◽  
Linear Rule ◽  
Distribution Rule ◽  
The Matrix ◽  
Nonhomogeneous Properties ◽  
Structure Strength

To study the effects of the nonhomogeneous material properties on the stress in an induction quenched crankshaft, the FEM model considering the nonhomogeneous material properties was established to simulate the stress in the crankshaft under the explosion pressure. Results showed that the nonhomogeneous properties almost didn’t vary the Mises stress distribution rule in the crankshaft. The maximum Mises stress, the ratio of the elastic modulus of the surface layer and the matrix followed a linear rule nearly. Moreover, the maximum Mises stress increased with the ratio. Besides, effect of elastic modulus distribution in the transition layer on the maximum stress could be ignored. To simplify the establishment of the FEM model, the elastic modulus could be set to either equal to the surface layer’s or the matrix’s.

Interface Transition Zone and the Elastic Modulus of Cement-Based Composites

1994 ◽  
Vol 370 ◽  
Author(s):  
Peter I. Simeonov ◽  
S.H. Ahmad
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Transition Zone ◽  
Material Properties ◽  
General Trend ◽  
Two Phase ◽  
Interface Transition Zone ◽  
The Matrix ◽  
Approach Zero ◽  
Highly Porous

AbstractThe influence of the Interface Transition Zone (ITZ) on the elastic modulus of concrete is demonstrated as a divergence of the experimental data from the general trend of the theoretical Hashin-Shtrikman bounds. This divergence is well related to the W/C of the composite. With reduction of W/C the influence of ITZ decreases and for values close to 0.4 and lower it is insignificant.The formation of the ITZ is characterized by a transfer of water from the matrix to the surface of the aggregates. As a result of this a highly porous ITZ is formed while the matrix remains with a reduced porosity. This process can also be described as a transfer of material properties. For some compositions the balance of this transfer can approach zero. The imbalance in this process is more pronounced at higher W/C.The effect of Interface Transition Zone can be successfully simulated by the help of recently derived Hashin's variational bounds for two-phase composites with imperfect interfaces.

scholarly journals A Study on Material Properties of Intermetallic Phases in a Multicomponent Hypereutectic Al-Si Alloy with the Use of Nanoindentation Testing

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5612
Author(s):  
Mirosław Tupaj ◽  
Antoni Władysław Orłowicz ◽  
Marek Mróz ◽  
Andrzej Trytek ◽  
Anna Janina Dolata ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Material Properties ◽  
Maximum Load ◽  
Intermetallic Phases ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Alloy Matrix ◽  
X Ray ◽  
Aluminum Silicon Alloy ◽  
The Matrix

The paper concerns modeling the microstructure of a hypereutectic aluminum-silicon alloy developed by the authors with the purpose of application for automobile cylinder liners showing high resistance to abrasive wear at least equal to that of cast-iron liners. With the use of the nanoindentation method, material properties of intermetallic phases and matrix in a hypereutectic Al-Si alloy containing Mn, Cu, Cr, Ni, V, Fe, and Mg as additives were examined. The scanning electron microscope equipped with an adapter for chemical composition microanalysis was used to determine the chemical composition of intermetallics and of the alloy matrix. Intermetallic phases, such as Al(Fe,Mn,M)Si, Al(Cr,V,M)Si, AlFeSi, AlFeNiM, AlCuNi, Al2Cu, and Mg2Si, including those supersaturated with various alloying elements (M), were identified based on results of X-ray diffraction (XRD) tests and microanalysis of chemical composition carried out with the use of X-ray energy dispersive spectroscopy (EDS). Shapes of the phases included regular, irregular, or elongated polygons. On the disclosed intermetallic phases, silicon precipitations, the matrix, values of the indentation hardness (HIT), and the indentation modulus (EIT) were determined by performing nanoindentation tests with the use of a Nanoindentation Tester NHT (CSM Instruments) equipped with a Berkovich B-L 32 diamond indenter. The adopted maximum load value was 20 mN.

scholarly journals Conventional Vickers and true instrumented indentation hardness determined by instrumented indentation tests

2010 ◽  
Vol 25 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Seung-Kyun Kang ◽  
Ju-Young Kim ◽  
Chan-Pyoung Park ◽  
Hyun-Uk Kim ◽  
Dongil Kwon
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Material Properties ◽  
Indentation Test ◽  
Indentation Hardness ◽  
Instrumented Indentation ◽  
Real Contact ◽  
Wide Range ◽  
Indentation Tests ◽  
Instrumented Indentation Test

We evaluate Vickers hardness and true instrumented indentation test (IIT) hardness of 24 metals over a wide range of mechanical properties using just IIT parameters by taking into account the real contact morphology beneath the Vickers indenter. Correlating the conventional Vickers hardness, indentation contact morphology, and IIT parameters for the 24 metals reveals relationships between contact depths and apparent material properties. We report the conventional Vickers and true IIT hardnesses measured only from IIT contact depths; these agree well with directly measured hardnesses within ±6% for Vickers hardness and ±10% for true IIT hardness.

Local Mechanical Properties of Cast and Sintered High Cr-Alloyed Steel

2013 ◽  
Vol 586 ◽  
pp. 241-244
Author(s):  
Ruslan Shvab ◽  
Pavol Hvizdoš ◽  
Eva Dudrová ◽  
Ola Bergman ◽  
Sven Bengtsson
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Chemical Composition ◽  
Sintered Material ◽  
Indentation Hardness ◽  
Instrumented Indentation ◽  
Indentation Method ◽  
Load Range ◽  
Cast Steels ◽  
Load Size

Local mechanical properties of high Cr-alloyed sintered and cast steels with the same chemical composition were investigated using instrumented indentation method. Standard loading/unloading mode was applied, the measurements were done in load range 1 – 500 mN. Load size effect was observed and its parameters were evaluated. Indentation hardness and elastic modulus were found slightly higher for the sintered material. Differences in indentation parameters were explained based on microstructure of materials.

scholarly journals Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548 ◽  
Author(s):  
Leonid Agureev ◽  
Valeriy Kostikov ◽  
Zhanna Eremeeva ◽  
Svetlana Savushkina ◽  
Boris Ivanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Strength Properties ◽  
Alumina Nanoparticles ◽  
Metal Powders ◽  
Wide Range ◽  
The Matrix ◽  
Spark Plasma ◽  
Average Size

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.

The effect of composition and cooling rate on the structure of rapidly solidified (Fe, Ni)3Al–C alloys

1989 ◽  
Vol 4 (1) ◽  
pp. 44-49 ◽  
Author(s):  
S. A. Myers ◽  
C. C. Koch
Keyword(s):  
Cooling Rate ◽  
Base Alloy ◽  
Weight Percent ◽  
Quench Rate ◽  
Transmission Electron ◽  
Metastable Structures ◽  
Metastable Structure ◽  
The Matrix ◽  
Rapidly Solidified ◽  
Kinetics Of

There is controversy in the literature regarding the existence of the metastable γ′ phase with an ordered Ll2 structure in rapidly solidified Fe–Ni–Al–C alloys. In this study, the quench rate–metastable structure dependence was examined in the Fe–20Ni–8Al–2C (weight percent) alloy. The effect of silicon on the kinetics of phase formation was studied by adding two weight percent silicon to a base alloy of Fe–20Ni–8Al–2C. Samples were rapidly solidified in an arc hammer apparatus and examined by transmission electron microscopy. In the Fe–20Ni–8Al–2C alloy, the nonequilibrium γ′ and γ phases were found in foils 65 to 100 μm thick. At higher quench rates, i.e., thinner samples, the matrix was observed to be disordered fcc γ with K-carbide precipitates. Samples containing silicon were found to have a matrix composed of γ′ and γ structures when the foils were thicker than 40 μm. At higher quench rates, the matrix was disordered fcc γ with K-carbide precipitates. The nonequilibrium γ′ and γ structures are present in samples with or without silicon, but are observed at higher cooling rates with the addition of silicon. This sensitivity to cooling rate and composition in resulting metastable structures may explain the differences reported in the literature for these rapidly solidified materials.

On Determining Elastic Modulus from Instrumented Indentation

2013 ◽  
Vol 668 ◽  
pp. 616-620
Author(s):  
Shuai Huang ◽  
Huang Yuan
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Plastic Material ◽  
Instrumented Indentation ◽  
Computational Simulations ◽  
Elastic Plastic ◽  
Modified Method ◽  
Plastic Materials ◽  
Elastic Plastic Material ◽  
Elastic Plastic Materials

Computational simulations of indentations in elastic-plastic materials showed overestimate in determining elastic modulus using the Oliver & Pharr’s method. Deviations significantly increase with decreasing material hardening. Based on extensive finite element computations the correlation between elastic-plastic material property and indentation has been carried out. A modified method was introduced for estimating elastic modulus from dimensional analysis associated with indentation data. Experimental verifications confirm that the new method produces more accurate prediction of elastic modulus than the Oliver & Pharr’s method.

The Effect of Cross-Linking on Nano-Mechanical Properties of Polyamide

2016 ◽  
Vol 699 ◽  
pp. 37-42 ◽  
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Martin Reznicek
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Material Properties ◽  
Basic Material ◽  
Nanoindentation Test ◽  
Cross Linking ◽  
Indentation Hardness ◽  
Depth Sensing ◽  
Nanomechanical Properties ◽  
Radiation Crosslinking

Radiation crosslinking of polyamidu 6 (PA 6) is a well-recognized modification of improving basic material characteristics. Radiation, which penetrated through specimens and reacted with the cross-linking agent, gradually formed cross-linking (3D net), first in the surface layer and then in the total volume, which resulted in considerable changes in specimen behaviour. This research paper deals with the possible utilization of irradiated PA6. The material already contained a special cross-linking agent TAIC (5 volume %), which should enable subsequent cross-linking by ionizing β – radiation (15, 30 and 45 kGy). The effect of the irradiation on mechanical behavior of the tested PA 6 was investigated. Material properties created by β – radiation are measured by nanoindentation test using the DSI method (Depth Sensing Indentation). Hardness increased with increasing dose of irradiation at everything samples; however results of nanoindentation test shows increasing in nanomechanical properties of surface layer. The highest values of nanomechanical properties were reached radiation dose of 45 kGy, when the nanomechanical values increased by about 95%. These results indicate advantage cross-linking of the improved mechanical properties.

Fabrication and Mechanical Properties of Dense/Porous β-Tricalcium Phosphate Bioceramics

2007 ◽  
Vol 330-332 ◽  
pp. 907-910
Author(s):  
Fa Ming Zhang ◽  
Jiang Chang ◽  
Jian Xi Lu ◽  
Kai Li Lin
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Exponential Growth ◽  
Weight Bearing ◽  
Area Ratio ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Matrix ◽  
Porous Bioceramics

Attempt to increase the mechanical properties of porous bioceramics, a dense/porous structured β-TCP bioceramics that mimic the characteristics of nature bone were fabricated. Experimental results show that the dense/porous structured β-TCP bioceramics demonstrated excellent mechanical properties with compressive strength up to 74 MPa and elastic modulus up to 960 MPa, which could be tailored by the dense/porous cross-sectional area ratio obeying the rule of exponential growth. The interface between the dense and porous bioceramics is connected compactly and tightly with some micropores distributed in the matrix of both porous and dense counterparts. The dense/porous structure of β-TCP bioceramics may provide an effective way to increase the mechanical properties of porous bioceramics for bone regeneration at weight bearing sites.

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