Question

Superalloys have been made of nickel and aluminum. The alloy owes its strength to the formation of an ordered phase, called the gamma-prime phase, in which Al atoms are at the corners of a cubic unit cell, and Ni atoms are at the face centers. What is the composition (relative numbers of atoms) for this phase of the nickel-aluminum superalloy?

Short answer

Superalloys are made of nickel and aluminum. The alloy owes its strength to forming an ordered phase, called the gamma-prime phase, in which Al atoms are at the corners of a cubic unit cell, and Ni atoms are at the face centers.

Step-by-step solution

Given Information

Superalloys are made of nickel and aluminum

Concept Introduction

Super alloy is a high-performance alloy; it is essential for the materials at high temperatures and is used in a high section of jets. They have good mechanical strength, resistance to thermal creep deformation, good surface stability, and resistance to corrosion or oxidation.

Explanation

Al atoms are at the corners of a cubic unit cell, and Ni atoms are at the face centers.

$$\begin{gathered} 8\mathrm{Corners}\times \left(\frac{1}{8}\mathrm{Al}\right)/\mathrm{Corner}=1\mathrm{Al}\mathrm{ion} \\ 6\mathrm{Faces}\times \left(\frac{1}{2}\mathrm{Ni}\right)/\mathrm{face}=3\mathrm{Ni}\mathrm{ions} \end{gathered}$$

${\mathrm{NiAl}}_3$is the composition of this alloy.

Superalloys are made of nickel and aluminum. The alloy owes its strength to forming an ordered phase, called the gamma-prime phase, in which Al atoms are at the corners of a cubic unit cell, and Ni atoms are at the face centers.