Elastic Moduli of Gray and Nodular Cast Iron

1980 ◽  
Vol 47 (4) ◽  
pp. 821-826 ◽  
Author(s):  
G. R. Speich ◽  
A. J. Schwoeble ◽  
B. M. Kapadia
Keyword(s):  
Cast Iron ◽  
Elastic Moduli ◽  
Elevated Temperatures ◽  
Gray Cast Iron ◽  
Volume Fraction ◽  
Nodular Cast Iron ◽  
Theoretical Models ◽  
Two Phase ◽  
Wave Technique ◽  
Pulse Echo

The elastic moduli of both gray and nodular cast iron were measured by a pulse-echo elastic-wave technique at ambient and elevated temperatures up to 760°C. When compared at similar graphite contents, the elastic moduli of gray cast iron were much lower than those of nodular cast iron. These results are satisfactorily explained by theoretical models for the elastic moduli of two-phase solids which take into account not only the volume fraction but also the shape of the graphite particles. The temperature-dependence of the elastic moduli of both gray and nodular cast iron can also be correctly predicted from these same models.

scholarly journals Three-dimensional CFD modeling of thermal behavior of a disc brake and pad for an automobile

2020 ◽  
Vol 15 (4) ◽  
pp. 543-549
Author(s):  
Haydar Kepekci ◽  
Ergin Kosa ◽  
Cüneyt Ezgi ◽  
Ahmet Cihan
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Elevated Temperatures ◽  
Gray Cast Iron ◽  
Three Dimensional ◽  
Brake System ◽  
Gray Cast ◽  
Cfd Modeling ◽  
Disc Brake ◽  
Disc Material

Abstract The brake system of an automobile is composed of disc brake and pad which are co-working components in braking and accelerating. In the braking period, due to friction between the surface of the disc and pad, the thermal heat is generated. It should be avoided to reach elevated temperatures in disc and pad. It is focused on different disc materials that are gray cast iron and carbon ceramics, whereas pad is made up of a composite material. In this study, the CFD model of the brake system is analyzed to get a realistic approach in the amount of transferred heat. The amount of produced heat can be affected by some parameters such as velocity and friction coefficient. The results show that surface temperature for carbon-ceramic disc material can change between 290 and 650 K according to the friction coefficient and velocity in transient mode. Also, if the disc material gray cast iron is selected, it can change between 295 and 500 K. It is claimed that the amount of dissipated heat depends on the different heat transfer coefficient of gray cast iron and carbon ceramics.

On a Spring-Network Model and Effective Elastic Moduli of Granular Materials

1999 ◽  
Vol 66 (1) ◽  
pp. 172-180 ◽  
Author(s):  
K. Alzebdeh ◽  
M. Ostoja-Starzewaski
Keyword(s):  
Granular Materials ◽  
Disordered Systems ◽  
Granular Media ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Effective Medium ◽  
Solid State Physics ◽  
Two Phase ◽  
Effective Medium Theories ◽  
The Individual

Two challenges in mechanics of granular media are taken up in this paper: (i) development of adequate numerical discrete element models of topologically disordered granular assemblies, and (ii) calculation of macroscopic elastic moduli of such materials using effective medium theories. Consideration of the first one leads to an adaptation of a spring-network (Kirkwood) model of solid-state physics to disordered systems, which is developed in the context of planar Delaunay networks. The model employs two linear springs: a normal one along an edge connecting two neighboring vertices (grain centers) which accounts for normal interactions between the grains, as well as an angular one which accounts for angle changes between two edges incident onto the same vertex; edges remain straight and grain rotations do not appear. This model is then used to predict elastic moduli of two-phase granular materials—random mixtures of soft and stiff grains —for high coordination numbers. It is found here that an effective Poisson’s ratio, νeff, of such a mixture is a convex function of the volume fraction, so that νeff may become negative when the individual Poisson’s ratios of both phases are both positive. Additionally, the usefulness of three effective medium theories—perfect disks, symmetric ellipses, and asymmetric ellipses—is tested.

Grey Cast Iron Strength аs Function оf Primary Austenite Dendrites Volume Fraction

2020 ◽  
Vol 299 ◽  
pp. 729-733
Author(s):  
A.A. Baron ◽  
L.V. Palatkina ◽  
I.L. Gonik
Keyword(s):  
Composite Material ◽  
Cast Iron ◽  
Ultimate Strength ◽  
Primary Structure ◽  
Gray Cast Iron ◽  
Volume Fraction ◽  
Grey Cast Iron ◽  
Gray Cast ◽  
Grey Cast ◽  
Quantitative Contribution

On the basis of approach to primary structure of gray cast iron as to an analog of the composite material, reinforced by discrete fibers, the quantitative contribution of dendritic crystals and the eutectic matrix to ultimate strength in tension is defined.

Direct Diode Laser Surface Melting of Nodular Cast Iron

2015 ◽  
Vol 809-810 ◽  
pp. 423-428 ◽  
Author(s):  
Damian Janicki
Keyword(s):  
Cast Iron ◽  
Diode Laser ◽  
Heat Input ◽  
Volume Fraction ◽  
Residual Austenite ◽  
Nodular Cast Iron ◽  
Surface Melting ◽  
Laser Surface ◽  
Test Method ◽  
Laser Surface Melting

A nodular cast iron (NCI) has been surface melted using the high power direct diode laser (HPDDL) with a quasi-rectangular laser beam spot and the uniform distribution of power. The effect of a heat input and a shielding gas on the quality of surface melted layers (SMLs) has been investigated. The microstructure of the SMLs has been assessed by optical microscopy, scanning electron microscopy and X-ray diffraction (XRD). Comparative erosion tests between the SMLs and as-received NCI have been performed following the ASTM G 76 standard test method. The HPDD laser surface melting of the NCI enables to produce non-porous layers having a hardness up to 1000 HV. It has been determined that the hardness of SMLs depends on the amount of cementite and residual austenite in the fusion zone. The SMLs produced in an argon atmosphere contain higher volume fraction of austenite, than those produced in nitrogen, and consequently have the lower hardness. With increasing heat input the hardness increases, as the result of more complete dissolution of graphite and the higher amount of cementite. The SMLs exhibited significantly higher erosion resistance than the as-received NCI for erodent impact angle of 3<em>0°, and slightly lower at 90°.</em><em></em>

scholarly journals Galvanic Corrosion of Ductile Cast Iron Coupled with Different Alloys in Synthetic Domestic Waste Water

2019 ◽  
Vol 70 (2) ◽  
pp. 506-511 ◽  
Author(s):  
Cristian Savin ◽  
Carmen Nejneru ◽  
Manuela Cristina Perju ◽  
Costica Bejinariu ◽  
Diana Burduhos-Nergis ◽  
...  
Keyword(s):  
Waste Water ◽  
Cast Iron ◽  
Gray Cast Iron ◽  
Galvanic Corrosion ◽  
Nodular Cast Iron ◽  
Ductile Cast Iron ◽  
Aluminum Bronze ◽  
Metallic Materials ◽  
Low Alloy Steel ◽  
Domestic Waste

Waste water is an aggressive environment for transport pumps to treatment plants. The pumps used are generally, immersion pumps and are made of various elements like, rotor, stator, housing, screws, flanges, springs, seals, etc. The construction elements of the pumps are made of various metallic materials, such as nodular cast iron, gray cast iron, low alloy steel, stainless steel, aluminum, bronze, brass, copper, etc. When immersed in waste water, the metals form galvanic series. The paper presents the galvanic corrosion analysis of the above-mentioned metals in case the corrosive environment is waste water with various compositions.

Elastic Moduli of Composites Reinforced by Multiphase Particles

1995 ◽  
Vol 62 (4) ◽  
pp. 1023-1028 ◽  
Author(s):  
M. L. Dunn ◽  
H. Ledbetter
Keyword(s):  
Elastic Moduli ◽  
Aluminum Matrix ◽  
Recent Analysis ◽  
Simple Extension ◽  
Two Phase ◽  
Elastic Fields ◽  
Three Phase ◽  
Theoretical Predictions ◽  
Concentration Factors ◽  
Pulse Echo

A theoretical approach is proposed to estimate the elastic moduli of three-phase composites consisting of a matrix phase reinforced by two-phase particles. The theoretical predictions are based on a simple extension to nondilute concentrations of the mechanical concentration factors obtained from the recent analysis of the average elastic fields in a double inclusion by Hori and Nemat-Nasser (1993). The proposed micromechanics theory can account for the effects of shapes and concentrations of both the particles and the dispersed phase in the particles. Theoretical estimates of the concentration factors and the effective elastic moduli are obtained in closed form and are diagonally symmetric and fall within the Hashin-Shtrikman-Walpole bounds for all cases considered. The theoretical predictions are in excellent agreement with experimental results obtained from pulse-echo and rod-resonance measurements of the elastic moduli of a three-phase composite consisting of an aluminum matrix reinforced by mullite/alumina particles.

Empirical Comparison of Sliding Friction and Wear Behaviors of Gray and White Cast Iron

2010 ◽  
Author(s):  
Mehdi Hashemi ◽  
Rahmatollah Ghajar
Keyword(s):  
Cast Iron ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Gray Cast Iron ◽  
White Cast Iron ◽  
Volume Fraction ◽  
Gray Cast ◽  
Graphite Flake ◽  
Lubricant Property ◽  
Wear Tests

In this paper, sliding friction and wear behaviors of gray cast iron A35 and white cast iron manufactured by quenching from the same cast iron in water were studied and compared by employing pin-on-disk wear tests. Microstructure of the worn surfaces before and after the wear tests were investigated by optical microscope observations. These images show that flakes separated from the surface in gray cast iron due to delamination process, while in white cast iron, the separation of materials from its surface is in the form of powder. In addition, the gray cast iron had higher graphite volume fraction with Type-A graphite flake morphology. The results show that white cast iron has less rate of wear than gray cast iron due to the higher hardness. However, gray cast iron because of presenting graphite flakes in its surface (lubricant property) has lower average coefficient of friction.

Determination of the relationship between microstructure and constitutive behaviour of nodular cast iron with a unit cell model

2005 ◽  
Vol 40 (2) ◽  
pp. 107-116 ◽  
Author(s):  
L Collini ◽  
G Nicoletto
Keyword(s):  
Cast Iron ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Cell Model ◽  
Nodular Cast Iron ◽  
Unit Cell ◽  
Constitutive Law ◽  
Cast Irons ◽  
Present Contribution ◽  
The Matrix

Unit cell models have been proposed to predict the constitutive law and failure of ductile materials with complex microstructures, such as ferritic nodular cast iron and particulate metal matrix composites (PMMCs). The present contribution aims to extend this modelling approach to the prediction of the constitutive response of nodular cast iron with a mixed ferritic/pearlitic matrix. The finite element method is used within the framework of continuum mechanics to carry out the calculations. The effect of some microstructural features, such as graphite volume fraction and ferrite-pearlite ratio of the matrix, on the mechanical performance is determined. The computational results are compared to results obtained in a previous experimental activity on nodular cast irons.

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