North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

Examples of Cavitation Effect in Die Casting

G. L. Lockwitz

Harley-Davidson Motor Co.

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

Universal Die Casting in 1980’s• Zinc tool• Wind Split molding – car hood• Cast holding studs

SpecsH-13

130 ft/sec46-48 Rc

400 degrees surface of steelPour about 850 degrees

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

Universal Failure

• Sampling ran 50 shots• Took out for die prep• Large pit in cover half

about .020 dia and .050-.010 deep

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

Cavitation 50 shots

GatePit in this area

Wind split molding

Side view of casting sectionwith cast stud

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

Stopped Cavitation Effect• Welded pit• Eyebrow added to gate in line with flow• Diverted metal which changed pressure drop• Ran 100,000+ with no further problem.• Effectively the eyebrow did not allow a local pressure drop in this area to fall below the vapor pressure of

the zinc• Cavitation inception did not occur

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

The fix – change flow pattern

GateWind split molding

Diverter in gate

Side view of casting sectionwith cast stud

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

H-D Rocker Cover

• High Cosmetic requirement• Early die replacement (25K shots)• Cavitation effect on fillets and radii• Excellent die tracking by caster• Photos taken every 5,000 shots

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

Harley Rocker Cover #89 – 35,000 ShotsCasting Photos

Gated on this side

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

#103 Rocker – 65,000 Shots

North American Die Casting Association – 114th Metalcasting CongressCastExpo’10, March 20-23, 2010 Orlando, Florida USA

AFS NADCA

#104 Rocker – 61,600 Shots