Thermal expansion coefficients are usually given as an average value for a certain temperature range.
In reality there are non-linearities over large ranges - the range of temperature differences we're working with is definitely large enough that this is a concern.
If I can verify the expansion coefficient of alloys are not noticeably affected by the alloying elements, I'll see if I can implement polynomials for thermal expansion coefficients.
Maybe it isn't worth the hassle - from 300 K to 1000 K the difference is only about 20%, so it might be easier to just use the 1000 K value for all temperatures as a worst case
Thermal expansion coefficients are usually given as an average value for a certain temperature range. In reality there are non-linearities over large ranges - the range of temperature differences we're working with is definitely large enough that this is a concern.
If I can verify the expansion coefficient of alloys are not noticeably affected by the alloying elements, I'll see if I can implement polynomials for thermal expansion coefficients.