Structure.homework #1-answer - MTLE-2100 Structure of...

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

MTLE- 2100 Structure of Engineering Materials, Homework # 1--Answer 1. Assume zone axis [h k l]. For the three planes to belong to this zone, the dot product between the zone axis and the plane normal has to be perpendicular. Therefore, for ) 00 1 ( - h = 0 ……. .(1) ) 11 3 ( - 3h + k + l = 0 ……. .(2) ) 2 3 1 ( - h - 3k + 2l = 0 ……. .(3) From (1) h = 0. Substituting to (2) and (3) k = - l and 3k = 2l. The only solution is [000]. The three planes do not belong to a zone axis. 2. c/a in hexagonal Triangular pyramid shape. 2x height of the pyramid = c, 2r = a. From the corner to the center of the triangle = 2r/ 3 (2r) 2 = h 2 + (2r/ 3) 2 h = 4r 2 -4r 2 /3 = 2r 2/3 c =2h = 4r 2/3 c/a = (4r 2/3)/2r = 2 2/3 = 1.633 3. FCC 4 atoms/unit cell 4 octahedral sites: one in body-center, one on 12 edges, each shared by four unit cells—(1/4)x 12 = 3. Total 12 sites. 8 tetrahedral sites—behind 8 corners. HCP

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.

This note was uploaded on 04/29/2008 for the course MTLE 2100 taught by Professor Tomozawa during the Spring '08 term at Rensselaer Polytechnic Institute.

Page1 / 2

Structure.homework #1-answer - MTLE-2100 Structure of...

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

View Full Document
Ask a homework question - tutors are online