How to make Castings more Sustainable

There are several ways to improve sustainability. These methods can also be combined to increase the advantage. But what are the ways:

Reduce the mass of the castings: Some castings are not as optimized as they can be. A lot of wall thicknesses are chosen because of the flow and solidification behavior instead of the load-bearing aspect. But most castings in an automotive application are quite optimized for minimal weight. So, the only way to reduce the weight of the casting is to reduce the wall thickness. Therefore, the mechanical properties need to be better than the current specifications.
Reduce the carbon footprint of the alloy: The carbon footprint of Aluminium alloys is strongly dependent on the energy used to make them. It ranges from 0.14 to 22 kg CO2 per kg Al. The easiest way is to use secondary alloys from post-consumer scraps. But that is not always possible and heavily depends on the alloy supplier. Also limiting factors are the iron, copper, and zinc content in these scraps.
Increase the tool lifetime: The tools also impact the carbon footprint of the later product. The steel must be made, machined, heat treated, and delivered. Increasing the tool’s lifetime reduces the casting’s carbon footprint by dividing the tool’s carbon emissions by a large number of parts.
And there are many more things to consider.

Rheocasting is the key to more sustainable castings. With Rheocasting higher iron contents can be cast without impacting the mechanical properties. Even with high iron secondary alloys, high strength and ductility can be achieved. With that head room in mechanical properties and better flow behavior, the wall thicknesses can be reduced to save weight. Also, there is no need to add 10% silicon to the alloy. 5% silicon is more than enough. This fact alone saves about 0.3 to 0.5 kg CO2 per kg Al.

After adaptation of the ingate system from HPDC to Rheocastings, low plunger speeds can be set as low as 0.3 m/s in the second phase. This increases the tool lifetime to 200% of the HPDC tool lifetime.

Does that sound interesting to you? Schedule a free consultation below for more information regarding your specific application.