Page 446 - 04. Subyek Engineering Materials - Manufacturing, Engineering and Technology SI 6th Edition - Serope Kalpakjian, Stephen Schmid (2009)

26 Chapter 16 Sheet-Metal Forming Processes and Equipment

(H) (D)
FIGURE l6.53 Hammering of cymbals. (a) Automated hammering on a peening machine;
(b) hand hammering of cymbals. Source: Courtesy of W Blanchard, Sabian Ltd.

“Turkish dish” form that controls the cymbal’s musicians prefer the natural surface appearance and
pitch. sound of formed, hot-rolled bronze. More commonly,
Automatic peen-forming is done on machinery the cymbals are lathe turned (Without any machining
without templates, since the cymbals have already fluid) in order to remove the oxide surface and reduce
been pressed into shape, but the pattern is controllable the thickness of the cymbal to create the desired
and uniform. The size and pattern of the peening Weight and sound. As a result of this process, the
operations depend on the desired response, such as surface finish becomes lustrous and, in some cases,
tone, sound, response, and pitch of the cymbal. The develops a favorable microstructure. Some cymbals
cymbals are then hammered to impart a distinctive are polished to a glossy “brilliant finish.” In many
character to each instrument. Hammering can be done cases, the surface indentations from peening persist
in automatic peen-forming machines (Fig. 16.53a) or after finishing; this is recognized as an essential
by hand (Fig. 16.53b). Hand hammering involves performance feature of the cymbal, and it is also an
placing the bronze blank on a steel anvil, where the aesthetic feature that is appreciated by musicians.
cymbals then are struck manually by hand hammers. Various surface finishes associated with modern
A number of finishing operations are performed cymbals are shown in Fig. 16.51b.
on the cymbals. These can involve merely the cleaning
and printing of identifying information, as some Source: Courtesy of W Blanchard, Sabian Ltd.

l6.l2 Manufacturing of Metal Honeycomb Structures

A honeycomb structure consists basically of a core of honeycomb or other corrugated
shapes bonded to two thin outer skins (Fig. 1654). The most common example of
such a structure is corrugated cardboard, which has a high stiffness-to-weight ratio
and is used extensively in packaging for shipping consumer and industrial goods