The material presented in this video are some highlights from NADCA’s online webinar – The Role of Die Casting Lubricants – presented by NADCA’s Beau Glim. Die lubricants are a necessary part of high pressure die casting. The lubricant provides a thin layer to protect the die steel from molten metal. The full presentation discusses what die lubricants are and characteristics important to die casting, how to apply die lubricants in operation, problems caused by improper use of die lubricants, and alternatives to conventional die lubricants.
Why do die lubricants help with cooling? Die lubricants, as you would receive them from the supplier are over 50% water. Typically for application use, die lubricants are diluted 80:1 to 120:1. That’s typical range but I’ve heard of 30:1 all the way up to 240:1. There’s a wide range of how much water is added to the lubricant when it is applied to the die surface, usually 99.5% is water. Water is being spray onto the die surface and that is what is causing the cooling. It’s going to turn into steam and it’s going to cool down the die surface. If you focus that spray into the hotter areas you can help balance what the die temperatures are.
What are lubricants? Lubricants are made up of a bunch of different additives. The most important additive is the anti-soldering additive. We’re looking to prevent any soldering of the metal to the die. We want to be sure that barrier is put into place and prevent any chemical reaction between the two metals. They also are going to have some metal flow additives to promote smooth metal flow over the die surface. For the hydrodynamic extreme pressure additives, you have a lot of moving parts that are inside the die such as slides and injector pins. This will help lubricant those moving parts. The lubricants will also have rust preventatives to help prevent and corrosion to the die surface. And then surfactants, these are going to be emulsifying components that help mix all the additives together and it can also modify the wettability or how well it adheres to the die surface. All of theses are mixed in some different variations to get a lubricant for the application you are looking for.
For information on purchasing a downloadable copy of this webinar in its entirety, please visit: http://www.diecasting.org/store/detail.aspx?id=WEB285