True, but it's even more complex.

Different materials exposed to the same heat source will experience different temperature changes.
At around 212°F, 1 gram of aluminum takes almost double the amount of heat (193%) to increase by 1° than 1 gram of iron.
This is one reason why the apparent expansion is not as close as the comparison between materials suggests.
This is counter-intuitive, because this factor (specific heat) is not related to heat transfer properties. Silver conducts heat even better than aluminum, but increases in temperature almost 5 times faster for the same heat input.

Don't try to calculate.