Solution5

# Solution5 - casting area no heat loss across this interface...

This preview shows pages 1–2. Sign up to view the full content.

HW 5 Solution 9-3 8 3 2 7 * 10 128 . 10 ) 420 )( / 1737 ( ) 273 1538 )( / 10 204 )( 2 ( × = + × = cm J cm J r cm 3 24 3 8 10 4352 ) 10 128 . 10 ( 3 4 cm V × = × = π 3 ) 92 . 2 ( ° = A V UC =24.897Å 3 =24.897×10 -24 cm 3 Number of unit cells 4352/24.897 = 175 Atoms per nucleus = (175 cells)(2 atoms/cell)=350 atoms 9-12

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
9-20 (a)T pour = 900 Cº (b) T sol = 420C º (c) ΔT s =900-420=480Cº (d) ΔT/Δt= 312 0 6 . 1 400 900 = Cº/min (e) t s =9.7 min (f) LST=9.7-1.6 min=8.1 min (g) 420-360 = 60Cº (h) Zn (i) t s =9.7=B[8/24] 2 B=87.5min/in 9-27 73 . 0 ) 4 )( 2 ( 1 ) 4 )( 4 ( 5 ) 4 )( 4 )( 4 ( ) / ( = + = thick A V 50 . 0 ) 2 )( 2 ( 2 ) 4 )( 2 ( 3 ) 4 )( 2 )( 2 ( ) / ( = + = thin A V 80 . 0 4 ) 4 / ( 2 ) 8 )( 4 ( ) 8 )( 4 )( 4 / ( ) / ( 2 2 = + = π Riser A V The area between the thick and thin sections of the casting are not included in calculating
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: casting area; no heat loss across this interface. The riser will not be effective; the thin section has the smallest V/A ration and therefore freezes first. Even though the riser has the longest solidification time, the thin section isolates the thick section from the riser, preventing liquid metal from feeding from the riser to the thick section. The shrinkage will occur in the thick section....
View Full Document

{[ snackBarMessage ]}

### Page1 / 2

Solution5 - casting area no heat loss across this interface...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online