Cast Component: Gimble housing. Material: A356 aluminum

 ast Component: Front steering knuckle.
C
Material: A356 aluminum with T6 heat treatment.
Process: Pressure-counter-pressure casting.
Casting Supplier: Intermet Corp., Stevensville Plant, Stevensville, Mich.
•The front steering knuckle was converted from a 20.1-lb. ductile
iron design into an 11.25-lb. aluminum component (a 44%
weight reduction) while maintaining the critical and safety
performance characteristics.
•The aluminum casting improves fatigue life of the component
and fills in gaps between aluminum and ductile iron or forged
steel where high strength and ductility are required. Conversion
to aluminum also provided easier machinability over ductile iron.
For more information, please circle No. 001 on Reader Action Card.
ast Component: Gimble housing.
C
Material: A356 aluminum.
Process: Plaster molding casting.
Casting Supplier: A.L. Johnson Co., Camarillo, Calif.
•Used in military applications, the cast component was originally
going to be produced as a CNC hog out. The 12-lb. casting is 13
in. in diameter and had a 13-in. cube of stock that needed to be
removed. Accomplishing this through another process would
have been too expensive.
•Sand casting was considered for the component, but with the
weight, undercut surfaces and the surface finish required, a considerable amount of machining also would be needed, further
adding to the cost.
•By casting the component through the plaster mold process, a
near-net-shape casting was produced with undercuts, thick and
thin sections, areas of no draft and excellent surface finish.
For more information, please circle No. 002 on Reader Action Card.
ast Component: Roller bracket.
C
Material: C-954 nickel-aluminum bronze.
Process: Permanent mold casting.
Casting Supplier: Piad Precision Casting Corp., Greensburg, Pa.
•The permanent mold process was used to cast the component,
which is used to raise and lower the squeegee on a walk-behind
industrial floor cleaner. The component was converted from a
seven-piece steel weldment.
•The original steel part required secondary surface protection,
which was eliminated by switching to a corrosion-resistant
nickel-aluminum-bronze alloy. The only machining required
is the drilling of two holes.
•By eliminating material from non-critical areas, overall part weight
was reduced 23%. Also, thinning out the two raised “ears” made them
more flexible, allowing for easier assembly with the mating part.
Cast Component: Rear rail for the Chevrolet Corvette convertible.
Material: AZ 91D magnesium.
Process: Thixomolding.
Casting Supplier: AFT, Denver, Colo.
•The rear rail serves as a structural part of the kinematic for the
convertible top and weighs 0.7 lbs, which is a significant reduction compared to an aluminum component.
•The thixomolding process extended tool life compared to diecasting. Changes in tooling also can be implemented easily at
lower costs. Thixomolding also provided the component with
fewer blow holes, less shrinkage, fewer hot cracks, less distortion
and higher dimensional accuracy.
For more information, please circle No. 003 on Reader Action Card.
For more information, please circle No. 004 on Reader Action Card.
January/February 2005
For Design Engineers & Purchasers
51
ast Component: Shift housing.
C
Material: AM60 magnesium.
Process: Laser sintering sand casting.
Casting Supplier: ACTech North America Inc., Belleville, Mich.
•The shift housing was produced via rapid prototyping utilizing
the laser sintering sand casting method. In this process, sand is
resin-bonded and exposed to two laser beams simultaneously,
which fuses the grains together, bonding them to the layer below
to form mold segments and cores.
•The casting, which will be converted to a die casting for highproduction, was prototyped to save costs and time to market. The
component is 10 x 6 x 5 in. and weighs 1 lb. The laser sintering
process doesn’t require tooling as the molds and cores are built from
CAD data. This casting was delivered 22 days after the metalcaster
received the final design data.
ast Component: Svi housing.
C
Material: 413F aluminum.
Process: Permanent mold.
Casting Supplier: Gupta Permold Corp, Pittsburgh, Pa.
•Used as a housing for electronics and computer circuitry of
industrial-grade control valve instruments, the cast component
weighs 2.1 lbs. and is 7 x 5 x 3.5 in.
•The casting was originally designed as a die casting, but the
conversion to permanent mold produced significant savings in
initial tooling costs. The component’s thick and thin sections
would have made it hard to produce via the diecasting process
so it was converted to a highly cored permanent mold casting
with complex parting. The casting is pressure-tight between
chambers without impregnation and achieves zero porosity
requirements after machining.
For more information, please circle No. 005 on Reader Action Card.
For more information, please circle No. 006 on Reader Action Card.
Circle No. 126 on Reader Action Card.
52Engineered Casting Solutions
Circle No. 134 on Reader Action Card.
January/February 2005