The Experimental Study of Nodular Cast Iron Volume Changes during Solidification

The volume changes during solidification of Nodular Cast Iron (NCI) in the sand mold studied using Linear Variable Differential Transformer (LVDT). Both hypo- and hyper-eutectic compositions are considered by adjusting the carbon fraction in the composition during the experimental studies. The microstructural analysis and measurements are taken from the samples to evaluate the different phases present, the nodule count and size distributions. At the beginning of solidification, the experimental result shows the volume change is negligible. During the eutectic growth, the samples expand until the end of solidification. The displacement measurement shows the expansion continued when solidification finished. The volume change studies during solidification indicate that as the carbon fraction increases the volume expansion decreases. On the other hand, it is found that the pore fraction decreases as the volume expansion decreases. The fraction of primary austenite decreases as the fraction of carbon increases, and that leads to having a lower pore fraction.

Download Full-text

Cellular Automaton Simulation For Volume Changes Of Solidifying Nodular Cast Iron

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0388 ◽

2015 ◽

Vol 60 (3) ◽

pp. 2379-2384 ◽

Cited By ~ 1

Author(s):

A. Burbelko ◽

D. Gurgul ◽

E. Guzik ◽

W. Kapturkiewicz

Keyword(s):

Cast Iron ◽

Cellular Automaton ◽

Weighted Average ◽

Nodular Cast Iron ◽

Phase Volume ◽

Volume Changes ◽

Phase Density ◽

Concentration Changes ◽

Nodular Graphite ◽

2D Space

AbstractVolume changes of the binary Fe-C alloy with nodular graphite were forecast by means of the Cellular Automaton Finite Differences (CA-FD) model of solidification. Simulations were performed in 2D space for differing carbon content. Dependences of phase density on temperature were considered in the computations; additionally density of the liquid phase and austenite were deemed as a function of carbon concentration. Changes of the specific volume were forecast on the base of the phase volume fractions and changes of phase density. Density of modeled material was calculated as weighted average of densities of each phase.

Download Full-text

The effects of carbon on the solidification of nodular cast iron– its study with the help of linear variable differential transformer and microstructural analysis

International Journal of Cast Metals Research ◽

10.1080/13640461.2017.1377382 ◽

2017 ◽

Vol 31 (2) ◽

pp. 108-117 ◽

Cited By ~ 4

Author(s):

Abel Tadesse ◽

Hasse Fredriksson

Keyword(s):

Cast Iron ◽

Microstructural Analysis ◽

Nodular Cast Iron ◽

Linear Variable Differential Transformer

Download Full-text

CT-measured regional specific volume change reflects regional ventilation in supine sheep

Journal of Applied Physiology ◽

10.1152/japplphysiol.00212.2007 ◽

2008 ◽

Vol 104 (4) ◽

pp. 1177-1184 ◽

Cited By ~ 76

Author(s):

Matthew K. Fuld ◽

R. Blaine Easley ◽

Osama I. Saba ◽

Deokiee Chon ◽

Joseph M. Reinhardt ◽

...

Keyword(s):

Volume Change ◽

Specific Volume ◽

Imaging Techniques ◽

Experimental Studies ◽

Region Of Interest ◽

Regional Ventilation ◽

Volume Changes ◽

Lung Expansion ◽

Wide Range ◽

Regional Lung

Computer tomography (CT) imaging techniques permit the noninvasive measurement of regional lung function. Regional specific volume change (sVol), determined from the change in lung density over a tidal breath, should correlate with regional ventilation and regional lung expansion measured with other techniques. sVol was validated against xenon (Xe)-CT-specific ventilation (sV̇) in four anesthetized, intubated, mechanically ventilated sheep. Xe-CT used expiratory gated axial scanning during the washin and washout of 55% Xe. sVol was measured from the tidal changes in tissue density (H, houndsfield units) of lung regions using the relationship sVol = [1,000(Hi − He)]/[He(1,000 + Hi)], where He and Hi are expiratory and inspiratory regional density. Distinct anatomical markings were used to define corresponding lung regions of interest between inspiratory, expiratory, and Xe-CT images, with an average region of interest size of 1.6 ± 0.7 ml. In addition, sVol was compared with regional volume changes measured directly from the positions of implanted metal markers in an additional animal. A linear relationship between sVol and sV̇ was demonstrated over a wide range of regional sV̇ found in the normal supine lung, with an overall correlation coefficient ( R2) of 0.66. There was a tight correlation ( R2 = 0.97) between marker-measured volume changes and sVol. Regional sVol, which involves significantly reduced exposure to radiation and Xe gas compared with the Xe-CT method, represents a safe and efficient surrogate for measuring regional ventilation in experimental studies and patients.

Download Full-text

The Effect of Inoculation on the Thermal Expansion/Contraction during Solidification of Gray Cast Iron

Materials Science Forum ◽

10.4028/www.scientific.net/msf.790-791.447 ◽

2014 ◽

Vol 790-791 ◽

pp. 447-451 ◽

Cited By ~ 5

Author(s):

Abel Tadesse ◽

Hasse Fredriksson

Keyword(s):

Cast Iron ◽

Gray Cast Iron ◽

Microstructural Analysis ◽

Experimental Results ◽

Experimental Result ◽

Gray Cast ◽

Austenite Formation ◽

Solidification Temperature ◽

Formation Region ◽

Eutectic Formation

Inoculation of casting used to improve the microstructure and the properties of the component. Depending upon the area of application, gray cast iron has different microstructure and mechanical properties. The type and amount of the inoculation result in shape and orientation differences of the flake graphite. The Linear Variable Differential Transformer (LVDT) shows a variation in displacements change during the solidification. Temperature measurement used to analyze cooling curves and microstructural analysis of sample to examine the physical differences. Thermal analysis compared with the experimental results and microstructural study for describing the variation in area fraction and shape of graphite. The experimental result indicates contraction in austenite formation region, and expansion in eutectic formation region. The effect of the inoculant and the superheat temperature shows a variation in degree of expansion/contraction and cooling rates of the experiments. The comparisons between the experimental and the theoretical results have been done. Combining the theoretical and experimental results, it resembles a difference in eutectic formation region, and it needs carful investigation in future works.

Download Full-text