Control of Aluminum Die Casting Defect

Defects and deformation might happen for some die casting parts.The quality of die casting parts will be guaranteed by optimizing structure of die casting parts,injection system and ventilation system.

  • Defects of aluminum die casting cover
    • The cover was made of ADC12 and requested high density and smooth surface,no burrs.The assembly area must contact firmly.The size of die casting parts is quite big and minimum wall thickness is 5mm.

There is deformation even crack caused by ejector pins on the edge of die casting parts.At the same time,there is cold shut in the area where two different molten alloy meet each other.Weiheng Die Casting is professional die casting manufacturer.

The defects might caused by following reasons

  1. The strength ejector pin apply is not evenly.Therefore,the die casting parts deformed and even cracks happen to some area.
  2. Hard to release off mold so strength of ejector pins is far too big.
  3. Diameter of ejector pins is too small and distribution over parts is not very good.
  4. The project dimension is too big so the deformation caused by cold shrinkage.
  5. The release agent not spray over the parts evenly and concentration of release agent is too low.
  6. The distance of sprue is too big so molted alloy via two runners can not meet quickly.
  7. Temperature of injection is low or temperature of mold is high.
  8. Ventilation is not good.
  9. The time for filling is too long.

2.1 Weiheng Die Casting suggestion for Improvement of structure of die casting parts.

The draft of die casting parts should increase,which can help castings released off mold.In addition,the reinforced rib should be added on to die casting parts,which can increase strength of die casting parts and keep it from deformation caused by cold shrinkage.

Die Casting Parts

Die Casting Parts

Adjust position of ejector pins and diameters and make them distribute over castings evenly.Relocate sprue,gate and runners onto side of casting,which does not affect outer looking of castings and make sprue cut easily.The distance of two gate can not be very long because long distance make two different molten alloy meet each other hardly.Also,air will be trapped into sprues.Therefore,it is necessary to design good sprues for die casting parts.For example,make whole united sprue instead of several separate sprues.When molted alloy leave from gate,its direction normally not vertical to gate,which is good for filling up cavity.Meanwhile,the air trapped will be reduced if smooth polishing the runners.

Ventilation can reduce porosity of casting and improve strength.Therefore,reasonable distribution of overflows is necessary for tooling.

Injection temperature is important for quality of die casting parts.Coating of cavity can keep castings from quick cooling down and reduce abrasion and soldering problem.Therefore,right proportion of coating need to be put onto cavities evenly.

To produce high quality die casting parts,it need all procedures operated properly.Like molten alloy,structure of die casting parts,injection system of tooling,ventilation layout,tooling assembly,die casting machining proformance,etc.

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