HW _1 - Unit Cells and Phase Diagrams

# HW _1 - Unit Cells and Phase Diagrams - you who have ever...

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

CEE 3020 Civil Engineering Materials Mr. Robert Moser Question 1 In the hard sphere model for an FCC structure, illustrated below, the atoms touch one another across a face-diagonal length which measures 4 R , where R is atomic radius. If the cube edge length is a , calculate the FCC unit cell volume, V c , in terms of R . Using this value, calculate the atomic packing factor (APF). How does this compare to BCC? Question 2 Consider the lead-tin phase diagram below. (The material may be familiar to those of

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: you who have ever soldered electronic equipment.) For each of the four points described, determine (a) which phases are present at the point (b) the composition of each phase, (c) the proportion of each phase, and (d) sketch the microstructure. The four points are: 1. 25 wt % tin +75 wt% lead at 170 C 2. 75 wt% tin + 25 wt% lead at 170 C 3. 5 wt% tin + 95 wt% lead at 170 C 4. 50 wt% tin + 50 wt% lead at 200C...
View Full Document

## This note was uploaded on 06/29/2009 for the course CEE 3020 taught by Professor Moser during the Spring '09 term at Georgia Tech.

### Page1 / 2

HW _1 - Unit Cells and Phase Diagrams - you who have ever...

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

View Full Document
Ask a homework question - tutors are online