*Heat Transfer Studies on Solidification of Casting Process DOI: http://dx.doi.org/10.5772/intechopen.95371*

*Casting Processes and Modelling of Metallic Materials*

**4.3 Behavior of IHTC for the given Al 6061**

*IHTC variation for the rectangular aluminum casting with sand mold.*

A sample of a rectangular geometry with an aluminum (Al6061) cast volume

Here the IHTC curve was calculated using the control volume method and it shows a gradual increase. Various characteristics of the IHTC and the heat transfer can be

The behavior of the sample rectangular cast was considered as it summarizes most of the heat transfer modes in solidification of the cast. On pouring the IHTC

perfect thermal contact. As further solidification starts, vaporization takes place in the sand mold because of the moisture content, presence of hydrogen release along with metal oxides across the interface and the reduction of specific volume of metal creates an air gap and decreases the value of IHTC rapidly to a minimum value of

the IHTC, then heat transfer reduces once the solid skin is formed [10]. Again the inner metal leaks and flows out from the solid skin to outside and gets cooled which again releases latent heat and so IHTC increases and decreases. Continuous rise and fall of the IHTC shows peak formation, which is shown till the end of solidification.

the sand mold is due to the escape of moisture content to the ambient, which is sufficient to allow the heat to flow from the solidifying metal to sand mold hence the sharp rise in IHTC is observed in the final stage of solidification. Not only vapor pressure but also huge temperature differences causes high heat flows. Due to the thermal resistance induced, as the metal solidifies and contracts, a fall in the IHTC

The materials that change phase during solidification to room temperature can be much more complicated. The heat transfer in the solidification is a complicated

K at 130 s. The shrinkage of metal causes release of latent heat and rise in

K at 90 s, the higher initial surface heat flux was due to a

K at 600 s and further again at 720 s the IHTC

K. The vapor pressure developed in

was solidified and the IHTC was calculated as shown below in **Figure 6**.

**50**

of 45 cm3

**Figure 6.**

discussed [9].

163 W/m<sup>2</sup>

is vividly observed.

**5. Conclusion**

was found to be 370 W/m2

The fourth peak value of 1718 W/m<sup>2</sup>

reached the highest peak value of 1918 W/m2

phenomenon as shown in the above sections. Understanding the heat transfer characteristics while solidification will help to link the various developments in the micro structure of the materials and the dislocations present. When solidification is complete the strength of the material can be assessed and the formation of the grains in the material can be directed by control of the temperature and heat flow on solidification.

The IHTC of a sample of Al6061 is thoroughly explained to comprehend the various modes of heat transfer while solidification is taking place. Proper cooling helps to govern the solidification and as the temperature is sufficiently low the strains of dislocations will not be sufficiently mobile to migrate into low energy positions, forming low-angle boundaries. Thus the alloy will become sufficiently strong to retain any further strain as elastic strain. Once the metal solidifies properly the structure of the alloy will no longer be affected during further cooling. Hence a complete idea of IHTC at all the times of solidification is the best option to minimize the errors and maximize the strength.
