METAL PROPERTIES, CHAR, USES, AND CODES - OD1643 - LESSON 1/TASK 1
kitchen utensils are made of aluminum.
Aluminum can be cast-forged, machined, and
(c) Limitations. Direct metal contact of aluminum with copper
and copper alloys should be avoided. Aluminum should also be used in
low temperature applications.
The chemical symbol for chromium is Cr, and its
ores are chromite and chrome ochre.
Chromium is one of the most versatile and widely
used alloys. It is used as an alloying agent in steel and cast iron
and in nonferrous alloys of nickel, copper, aluminum, and cobalt. It
is also widely used in electroplating for appearance and wear, in
powder metallurgy, and to make x-ray targets, mirrors, and stainless
Chromium is hard, brittle,
resistant, and can be welded, machined, and forged.
Chromium is not resistant to hydrochloric
acid, nor can it be used in the pure state because of its brittleness
and difficulty to work.
(3) Cobalt. The chemical symbol for cobalt is Co, and the chief
ores of cobalt are cobaltite and smaltite.
Cobalt is mainly used as an alloying element in
permanent and soft magnetic materials, high-speed tools bits and
carbide tool bits and cutters.
It is also used in making insoluble
Cobalt can be welded, limitedly machined,
Cobalt must be machined with cemented carbide
(4) C o p p e r .
The chemical symbol
copper produced today