tiatives and on the Sector Strategies Program, an initiative to develop performance improvement strategies for major
manufacturing and service sectors. The
American Foundry Society (AFS) represents the industry in this initiative.
Within the metalcasting sector, the
greatest opportunities for environmental improvements are in increasing
energy efficiency, managing and minimizing toxics and waste, reducing air
emissions, and conserving water.
A recent EPA Sector Strategies
Performance Report illustrates the
industry’s progress in these areas.
Energy Efficiency—The metalcasting
industry is one of the most energy-intensive industries in the U.S., so
reducing energy consumption is an
important economic and environmental
focus. In 2002, the metalcasting sector
consumed 165 trillion Btus of energy,
which was considerably lower than in
the last study in 1994.
Managing and Minimizing Toxics—The
release of chemicals into the air and
water also declined significantly with a
41% reduction between 1994 and 2003.
Managing Hazardous Waste—The metal-
casting industry accounted for less than
1% of the hazardous waste generated
nationally in 2003. Almost 70% of this
waste was generated by dip, flush or spray
rinsing and air pollution control devices.
Water Conservation—The metalcasting
industry is implementing a variety of
technologies used to lubricate and cool
dies during the diecasting process. These
include reusing non-contact cooling
water in other plant operations, installing
cooling towers and recovering surface
treatment chemicals.
Even with the dramatic reductions in
energy consumption, the metalcasting
industry continues to explore ways to
save energy, including:
; Replacing older melting furnaces
with modern batch melters, which
would improve energy efficiency
for this process by more than 32%
; Improving casting yield by 5% in
all metal casting industries except
ductile iron pipe, for an overall
tacit energy savings of 22. 7 trillion
Btus per year
; Applying existing air/natural gas
mixing methods to reduce ladle
heating energy by 10% to 30%
CASTING MANUFACTURING
ADVANCEMENTS
The versatility of metalcasting allows
designers to choose from a large number of processes and materials to
achieve the right combination for optimized success. However, it is essential
for those designers to understand the
relationship of processes and alloys to
unleash the power of metalcasting to
create effective components.
Metalcasting molding processes can
be broken into four general categories:
; sand casting processes
; ceramic processes
; permanent mold processes
; rapid prototyping.
Each process has specific methods for
metalcasting and offers advantages
when matched with the proper alloy and
application. However, not all metal
alloys can be cast in all molding processes. While almost all major alloys (except
those requiring a vacuum) can be cast in
the major sand processes, only nonferrous alloys such as aluminum, magnesium and zinc can be regularly cast via a
permanent (metal) mold process.
