Tuesday, June 13, 2023

The Shrinkage Factor Of Aluminum Bronze Material Explained















For various reasons, it is common for metal to shrink as it transforms from its liquid form to a solid form. It is important to gain an understanding of what to expect when working with metal so that allowances can be made when referring to the finished product. 

After all, shrinkage is not always visible. 


Let’s take a closer look at the shrinkage factor of aluminum bronze material, including what it is and why it happens. 


Understanding the Shrinkage Factor


When working with metal, it is important to understand that there will be a shrinkage factor you will need to consider. Without doing so, you can find yourself with a defective end product that leads to its inability to function properly. 


Aluminum bronze material, specifically, can encounter shrinkage at different steps, including: 


  • Liquid shrinkage. Shrinkage at this stage occurs before it begins to cool and harden. In other words, it can already begin to happen before the metal has cooled. 


  • Solidification shrinkage. Liquid aluminum alloy will shrink as it begins to solidify. The reason for this is that solid alloys are much more dense than liquid alloys. 


  • Pattern shrinkage. When a patternmaker begins to mark a metal once it has cooled, you risk shrinkage, as well.  


Factors the Impact the Shrinkage of Aluminum Bronze


There are a few factors that influence the shrinkage of aluminum bronze material, as well as other metals. These include things like the temperature at which it is poured, its chemical composition, the casting or mold conditions, and so forth. 


  • Pouring temperature. Simply stated, the higher the pouring temperature, the greater amount of shrinkage that will occur. 


  • Chemical composition. Different elements that are used to make up a metal or metal alloy will play a role in just how great or small the shrinkage is. 


  • Molds and Castings. The type of shrinkage that occurs here is the result of the mold itself. It is more of a blocked shrinkage due to the size and shape of the mold/casting. For instance, a mold’s design may cause different cooling rates. This can impact the finished product and its amount of shrinkage. 


What is the Shrinkage Factor of Aluminum Bronze? 


Remember, there are a number of factors that impact just how much metal will shrink - including aluminum bronze. Though, on average, you should expect your metal to shrink anywhere between 1.6% to 6%. 


Tips to Minimize Aluminum Bronze Shrinkage


Believe it or not, there are a few steps you can take to minimize the amount of shrinkage you encounter with your aluminum bronze. Below are a few tips to get you started. 


  • Make sure you control the temperature of your liquid metal as you pour it. 

  • Pour it fast.

  • Create a riser that will allow the additional liquid metal to compensate for shrinkage. 

  • Improve your casting structure


The more time you take to perfect your system, the greater chance you have of minimizing your metal’s shrinkage. 


Learn More About Working with Aluminum Bronze


Interested in working with aluminum bronze? At Atlas Bronze, we understand just how imperative it is to fully understand the metal you are working with if you want an end product that exceeds expectations. 


To learn more about aluminum bronze or any other metal your application calls for, contact us at (800) 478-0887.