Question

Ni has a density of 8.90 g/cm3 and Ti has a density of 4.5 g/cm3 . A binary NiTi alloy is 25 wt.% Ti. What is the composition of this alloy in vol.%. (10 points)

Answer 1

Answer : The composition of Ti and Ni alloy in vol.% is, 39.7 % and 60.3 % respectively.

Explanation :

As we are given that a binary NiTi alloy is 25 wt.% Ti. That means, 25 grams of Ti and 75 grams of Ni present in NiTi alloy.

Now we have to determine the volume of Ni and Ti.

$\text{Volume of Ti}=\frac{\text{Mass of Ti}}{\text{Density of Ti}}$

$\text{Volume of Ti}=\frac{25g}{4.5g/cm^3}=5.55cm^3$

and,

$\text{Volume of Ni}=\frac{\text{Mass of Ni}}{\text{Density of Ni}}$

$\text{Volume of Ni}=\frac{75g}{8.90g/cm^3}=8.43cm^3$

Now we have to calculate the composition of this alloy in vol.%.

$\% \text{Volume of Ti}=\frac{5.55cm^3}{5.55cm^3+8.43cm^3}\times 100=39.7\%$

and,

$\% \text{Volume of Ni}=\frac{8.43cm^3}{5.55cm^3+8.43cm^3}\times 100=60.3\%$

Thus, the composition of Ti and Ni alloy in vol.% is, 39.7 % and 60.3 % respectively.