Die casting is a metal casting process that injects molten metal through high pressure into a die. It is an economical process that can manufacture a high volume of parts. While die castings have a good surface finish, and are dimensionally accurate, porosity inside the part is inevitable.
Simply stated, porosity is any void or hole found within the casting. Porosity is inherent in die casting manufacturing. While economical, the high speed process of injecting molten metal into a die inherently creates porosity. The two most common types of casting porosity types are: gas porosity and shrinkage porosity.
Fully enclosed porosity is not a problem unless secondary machining uncovers this porosity. Machining can break fully enclosed porosity, which will then turn it to either Blind or Through porosity.
Causes of Porosity in Die Casting
- The design of the mold and cast parts
- The purity of the metal or alloy being used
- Pressure and shot speed of the machines
- Shrinkage of the material wall thickness
- Too much lubricant in the die
- Sharp corners in the mold
- Low metal temperatures
- Air trapped in the metal
The most common way to check for porosity is an X-ray of the material, using computerized tomography or by cutting and polishing a section and then analyzing it under a microscope.
How to Fix Die Casting Porosity?
Vacuum impregnation is a method that seals the casting resulting from porosity. The impregnating material is introduced into the voids within the wall thickness of the casting through vacuum and/or pressure methods. This method is a cost effective and permanent solution to casting porosity. There is no limit to the size of castings which can be impregnated.
A key characteristic of a successful impregnation process is that it seals the component without changing any of its assembly, functional or physical characteristics. Assembly characteristics include performance of tapped holes; the integrity of mating and sealing surfaces; and the elimination of residual contamination. Functional characteristics include the ability for fluids or gasses to flow only where needed in order to enhance in-service performance of the component’s design while physical characteristics, simply stated, are the component must not appear to be different in any manner.
If you’re concerned about the porosity of your casting, we recommend you contact us directly to learn more.
One-stop services of Die-casting & Custom Manufacturing in China
- State-of-the-art Die Casting Facilities : 60,000 sq. ft. die casting floor space in China, 30 die casting machines for aluminum, magnesium, and zinc;
- Get the features you need all from a single provide. In-house CNC machining allows JINGXIN Die Casting to machine any element your casting requires. The latest technology means you can expect high-quality, repeatable machining of any type. We want to be your one-stop-shop for CNC machining and die cast services.
- Post Finish : We offer a series of post finishing services for die casting parts. The finish includes painting, electroplating, printing, powder coating, anodizing, sand blasting, E-coating, polishing, and passivation;
- We are ISO 9001 certified and our customers include some of the world’s toughest. Read More Quality control in House
- Customer Service : Our highly skilled, English-speaking staff work directly with your design engineers every step of the way, from the design stage through product delivery. We own and manage the entire life cycle of a die casting manufacturing project.
What we do to make sure you would get the quality parts from JINGXIN Die Casting shop in China.
We declare here that We will be responsible for our precision Die Casting all the time.
1.100% inspection before shipping and inspection shipment report for each piece of precision Die Casting is available. (ISO quality control during the whole production).
2. We have served Volvo auto corp since 2016 as an approved precision CNC milling company in China. no complaint so far.
3. In case Any precision Die Casting that is outside tolerance and your special specification, we will remake and delivery as fast as we can; 100% free from our side.
4. For past years, JINGXIN Die Casting company has manufacturing thousands of pieces precision Die Casting components for our customers. 99.9% satisfaction feedback drives us to supply more quality precision machined parts to meet customer’s request.