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Die Casting Release and Plunger Lube Application to Reduce Porosity

Posted by Hill and Griffith Company on Nov 30, 2016 3:52:22 PM

th(This week's post is the combination of a review of the technical paper "Analyze of the Possible Causes of Porosity Type Defects in Aluminum High-pressure Diecast Parts" by Ferencz Peti and Lucian Grama; and 3D scanned images of die casting porosity from Exact Metrology thanks to Amy Cupp.)

Abstract

The most common defect that appears in castings is the porosity type of defect, which can be gas porosity, shrinkage porosity or leaker.

Die-Casting-Plunger-Lube-1.jpg

 

Porosity type of defects reduces the quality of the casting usually its tightness and strength.
 
Gas porosity can be described as trapped air in the casting which can come from several sources. It can be caused by poor shot end control, poor venting and overflow function or bad gating and runner design.
 
The shrinkage porosities can be described as internal cracks in the casting which can come from several sources, mainly due to thick walls of the casting. This defect is caused by metal reducing its volume during solidification and an inability to feed shrinkage with more metal before solidification. Hot spots can also cause shrinkage porosity to be concentrated in a specific zone.
 
Causes of leaks in castings where pressure tightness is required can be oxide folds and/or inclusion and/or porosity in conjunction with a surface defect which completes the part for a leak. A close analysis of the leaking area may reveal which of the many causes is causing the leak.
 
Die-Casting-Plunger-Lube-2.jpg
 
Included in the main causes for gas porosities are: Not enough plunger lube/sticking plunger;  Die is too cold; or Too much die spray.
 
Included in main causes for shrinkage porosities are: Not enough plunger lube/sticking plunger; Die is too hot; or Not enough die spray;  .
 
Included in the main causes for leaker are: Too much plunger lube; Not enough plunger lube/sticking plunger; Die is too cold;  Die is too hot; or Too much die spray.
 
State of the art the computerized tomography for the analysis of the porous defects in castings is used by companies such as VW group. With this method, the volume and localization of the porosities can be precisely determined and built in numerical 3D models. 
 
Die-Casting-Plunger-Lube-3.jpg
 
Summary
 
How to reduce porosity type of defects? The simplest way is to do a good process definition and setup since the beginning and to keep it under control by assuring the stability of the process. The stability of the process can be assured by monitoring and keeping under control the process parameters. The monitoring can be done automatically by the diecasting cell or with frequent controls defined in process failure mode analysis and in control plans. 

Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend die casting release agents, die casting lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

Hill and Griffith Samples

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We are pleased to provide samples in quantities large enough to allow you to "try before you buy." Die Casting and Squeeze Lubricants- Diluco®, Permanent Mold Coatings- Concote™, Plunger Lube™- Graphite and non-graphite oils and pastes with excellent anti-wear properties, Casting Operations Products: Start-up lubes, Ladle coatings, Anti-soldering pastes, Water glycol, Trim press lubricants, Surface protection for casting storage, Corrosion protection for die storage, Cleaners for machines and dies, Corrosion protection for machines, Heat treatment quenchants, and Heat-transfer fluids. Also, Industrial Lubricants Griflube®, Hydraulic fluids with fire-resistant and anti-wear properties, Bio-Syn natural ester-based hydraulic fluid, Way oil knuckle lubes and Metalworking Fluids- Grifcut™. Contact Us »

 

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On-site process surveys, Casting defect investigations, Product testing, Tooling start-ups and Statistical process controls and much more. Also, lab facilities are available to provide testing upon request. Contact Us »

 

Bulletins and Technical Papers for Die Casting Products

Tags: Die Casting, Metal Casting, Die Casting Adhesion Problems, diecast, diecasting, die casting award, Magnesium Die Casting

 


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend release agents, lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy." Die Casting and Squeeze Lubricants- Diluco®, Permanent Mold Coatings- Concote™, Plunger Lube™- Graphite and non-graphite oils and pastes with excellent anti-wear properties, Casting Operations Products: Start-up lubes, Ladle coatings, Anti-soldering pastes, Water glycol, Trim press lubricants, Surface protection for casting storage, Corrosion protection for die storage, Cleaners for machines and dies, Corrosion protection for machines, Heat treatment quenchants, and Heat-transfer fluids. Also, Industrial Lubricants Griflube®, Hydraulic fluids with fire-resistant and anti-wear properties, Bio-Syn natural ester-based hydraulic fluid, Way oil knuckle lubes and Metalworking Fluids- Grifcut™

Contact us for Product Samples

Hill and Griffith Customer Service

Technical Services & Support

On-site process surveys, Casting defect investigations, Product testing, Tooling start-ups and Statistical process controls and much more. Also, lab facilities are available to provide testing upon request. 

Contact us to Arrange a Visit

Bulletins and Technical Papers for Die Casting Products

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