What solidification time is required for a casting of $9.5 \mathrm{~cm}^3$ and a mold contact area of $10.0 \mathrm{~cm}^2$? The mold constant is $838 \mathrm{~s} / \mathrm{cm}^2$.

A 2-in. cube solidifies in $4.6 \mathrm{~min}$. Assume $n=2$. Calculate (a) the mold constant in Chvorinov's rule; and (b) the solidification time for a $0.5$ in. $\times$ $0.5$ in. $\times 6$ in. bar cast under the same conditions.

Find the mold constant $\mathrm{B}$ and exponent $n$ in Chvorinov's rule using the following data and a $\log -\log$ plot:Determine (a) the time at which solidification begins at the surface and (b) the time at which the entire casting is expected to be solid. (c) Suppose the center of the casting actually solidified in $720 \mathrm{~s}$. Explain why this time might differ from the time calculated in part (b).

Write down Chvorinov’s rule and explain the meaning of each term.

It is desired to increase the dendritic fraction from $0.012$ to $0.025$. Assuming that the specific heat of the metal being solidified is constant, determine the increase in the amount of undercooling required.

Define the following terms: nucleation, embryo, heterogeneous nucleation, and homogeneous nucleation.

Analysis of a nickel casting suggests that $28 \%$ of the solidification process occurred in a dendritic manner. Calculate the temperature at which nucleation occurred. The specific heat of nickel is $4.1 \mathrm{~J} /\left(\mathrm{cm}^3,{ }^{\circ} \mathrm{C}\right)$

Calculate the fraction of solidification that occurs dendritically when iron nucleates (a) at $10^{\circ} \mathrm{C}$ undercooling; (b) at $100^{\circ} \mathrm{C}$ undercooling; and (c) homogeneously. The specific heat of iron is $5.78 \mathrm{~J} /\left(\mathrm{cm}^3+{ }^{\circ} \mathrm{C}\right)$.

Calculate the fraction of solidification that occurs dendritically when silver nucleates (a) at $10^{\circ} \mathrm{C}$ undercooling; (b) at $100^{\circ} \mathrm{C}$ undercooling; and (c) homogeneously. The specific heat of silver is $3.25 \mathrm{~J} /\left(\mathrm{cm}^3 \cdot{ }^{\circ} \mathrm{C}\right)$.

What is a dendrite and why do dendrites form during solidification?

What is a dendrite and why do dendrites form during solidification?

Describe under what conditions we expect molten metals to undergo dendritic solidification.

During solidification, the specific heat of the material and the latent heat of fusion need to be removed. Define each of these terms.

What are the two steps encountered in the solidification of molten metals? As a function of time, can they overlap with one another?