controlling mechanical and material properties with alloy selection

The choice of alloy used in casting will determine the casting quality and material properties of the part, as well as the design functionality. Often, material selection reverts to what’s always been used, but higher performing, specially created alloys can now offer high performance combined with cost efficiency. 

How do you select the best alloy for your cast part?

It's vital to consider the final material properties you require in your part. Alloy selection will impact material properties such as:

• Corrosion resistance
• Thermal conductivity
• Hardness
• The metal behaviour at high temperatures (whether it does or does not contain silicon).

Selecting the alloy will depend on the type of prototype part you require, as well as how closely you need to replicate production processes (and material properties of the part) with a prototype.

Read more about the potential of sand casting for prototyping in our blog.

Which material properties do you require?

The different properties of alloys will affect your part's properties. For example, aluminium-silicon has high corrosion resistance compared an aluminium-copper alloy; but lower fatigue properties. Take a look at the table below for more information.

MODELLING ALLOY BEHVIOUR WITH SIMULATION prior to casting

The need to run multi-casting trials in the foundry can be removed with casting simulation. This provides vital information to allow the casting method to be refined, before a 'real' trial is carried out. This reduces potential cost, lead time and material usage.

Magma simulation has been refined over many years by comparing empirical results with predictions for different alloys and the parameters. As a result, the simulation can demonstrate the different results that can be achieved with different alloys, maximising the requirements to achieve final properties in the finished product. 

Magma simulation can also provide insight in the residual stress levels both in 'as cast' condition and also after heat treatment.

Alloy selection is an essential part of sand casting. To find out more about other steps in the process, as well as what sand casting can achieve, read our free eBook The Basics of the Sand Casting Process.