Question

Which of the following shows the relationship between the growth rate and inter-phase spacing?

(a) λ^2R = constant

(b) λR^2 = constant

(c) λ/R = constant

(d) λ⁴R = constant

I got this question during a job interview.

This interesting question is from Directional Solidification in chapter Pattern and Mould, Principles of Gating & Risering of Casting-Forming-Welding I

Answer 1

Correct choice is (a) λ^2R = constant

The best I can explain: The relationship between the growth rate (R) and inter-phase spacing (λ) for the eutectic structure is given by:  λ^2R = constant, where the constant is related to the magnitudes of the liquid-us slopes at the eutectic temperature and the composition difference between the two phases.