Hill and Griffith
Die Casting Defects - Causes and Solutions - NADCA Book
NADCA offers its book outlining the causes of die casting defects and how to prevent them
This is a comprehensive textbook for die casting engineers. This revised version of the defects causes and solutions book has been completely reviewed and revised by world renowned die cast experts William G. Walkington and Dr. Morris Murray. The book includes much more detail on the cures needed to reduce and/or eliminate the defects that plague all die casters. Dr. Murray discusses each defect, in depth, and provides thoughtful solutions to try to help mitigate the problems.
The book has also been updated to include metric units and information on the latest inspection instruments used in the identification and analysis of defects in die castings.
Chapter details are as follows:
Review - A review of some of the major operational practices required to reduce or eliminate effects. Just knowing the cause of the defect and asking for a correction won't fix the problem.
Surface Defects - Those defects commonly called cold flow or non-fills
Laminations - Defects from layers of metal forming during the process
Gas Porosity - Internal porosity from trapped gas of various kinds
Blisters - Surface manifestation of trapped gas
Flow Porosity - Surface or internal porosity from poor pressure conditions
Shrink Defects - Porosity from the volume change as the metal changes state
Sinks - Surface depressions from shrinkage porosity problems
Leakers - Porous sections of the casting
Cracks - Visible and not-so-visible cracks in the casting
Inclusions - Foreign material that may cause machining problems
Solder - Build up of the case material on the die, and damage to the surface condition of the casting
Carbon - Deposits other than the cast material on the die causing damage to the surface condition of the casting
Erosion or Cavitation - Removal of die steel and subsequent deformation of the casting
Outgassing & Edge Porosity - Gas escaping from the casting during a painting or finishing operation that causes defective surface finish
Bending, Warping - Deformation of the casting sometime after it is formed in the die cavity
Flash - Excessing material extending from a parting line, often accompanied by dimensional deviation
Stained Castings - Discolored castings
Waves and Lakes - Decorative castings with small imperfections visible only under reflected light
Drags - Surface area of the casting is broken by metal stuck to the die
Deformations from Ejector Pins - Casting is deformed by ejector pins (pushed pins)
Cold Flakes - Leakers and break in at the gate
Excessive Flux - Corrosion or porosity from excessive flux
Surface Defects - Defects that are caused by surface interaction with the die
To purchase the hard copy or download the e-version of this book, go to the NADCA site.
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