Page 297 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

276 Chapter 11 Metal-Casting Processes and Equipment

polished to the required dimensional tolerance and subjected to finishing operations to obtain the final
surface finish. Figure 11.17 shows the progression of product.
investment casting, from tree, to investment, to
casting. The parts are then removed from the tree and Source: Courtesy of M. Hawkins, Zimmer, Inc.

¢.¢f».»1¢¢.. W

(H) (D)

(C) (Ci)
FIGURE l.l6 Manufacture of total knee replacements. (a) The Zimmer NeXGen mobile-bearing
I
knee (MBK); the femoral portion of the total knee replacement is the subject of the case study.
(b) Assembly of patterns onto a central tree. (C) Dipping of the tree into slurry to develop a mold
from investment. (d) Pouring of metal into a mold. Source: Courtesy of M. Hawkins, Zimmer, Inc.

(8) (b) (C)
FIGURE II.l1 Progression of the tree. (a) After assembly of blanks onto the tree; (b) after
coating with investment; (c) after removal from the mold. Source: Courtesy of M. Hawkins,
Zimmer, Inc.