Try the fastest way to create flashcards
Question

# An Al-Si alloy contains $15 \%$ primary $\beta$ and $85 \%$ eutectic microconstituent immediately after the eutectic reaction has been completed. Determine the composition of the alloy. (See Figure 11-19.)

Solution

Verified
Step 1
1 of 2

Since the constituents present are the primary-$\beta$ and eutectic, the reaction occurs at a hypereutectic composition. The Al-Si alloy freezing range occurred at the $\beta+L$ region and after it cools past the eutectic temperature of $577^o\text{C}$, transformed into $\alpha+\beta$ with a primary-$\beta$ and eutectic constituents.

We will use the tie line at the hypereutectic region. The $\%\beta$ will already be the relative amount of primary-$\beta$ present, while the amount of $L$ will be the one that will transform into the eutectic constituent. We let $X$ to be the composition of the alloy.

$\%\beta:\frac{X-12.6}{99.83-12.6}=0.15\%\text{ primary-}\beta$

$X=\boxed{\text{Al-}25.68\%\text{Si}}$ ## Recommended textbook solutions #### Fundamentals of Electric Circuits

6th EditionISBN: 9780078028229 (2 more)Charles Alexander, Matthew Sadiku
2,120 solutions #### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

4th EditionISBN: 9780133942651 (8 more)Randall D. Knight
3,508 solutions  