The Chemical Composition of Casting Aluminum and Bronze
Casting is an important process for the production of metal items such as engine blocks and transmission cases. The two metals most commonly used in casting are aluminum and bronze. The chemical composition of these two metals is significantly different, and knowing the differences can help a manufacturer decide which one is the best choice for a particular project.
Aluminum is one of the most plentiful metals on Earth and is characterized by its light weight and high strength-to-weight ratio. It is an excellent choice when an item needs to be light but still have good strength. Aluminum is composed of 92.7 percent aluminum and the remainder is composed mostly of silicon, iron, copper, manganese, magnesium, and zinc. The exact mix of these elements can vary depending on the purpose of the casting. Aluminum castings are typically much lighter than steel and bronze castings.
Bronze is an alloy composed primarily of copper with other elements, such as tin, zinc, aluminum, manganese and iron. Bronze has many desirable characteristics, such as its strength, hardness, and resistance to corrosion. Bronze castings are much more expensive than aluminum, but they are also stronger and better suited for certain types of applications.
The chemical composition of casting aluminum and bronze will also affect their properties such as melting point, corrosion resistance, ductility, and hardness. Aluminum has a melting point of about 660°C and bronze has a melting point of about 900°C. Aluminum is highly resistant to corrosion and is relatively soft, making it easier to machine. Bronze, on the other hand, is extremely strong and hard but is also much less corrosion-resistant.
When choosing between casting aluminum and bronze for a specific application, it is important to consider all of the factors, such as their chemical composition, melting point, cost, and required strength and hardness. Knowing the differences between these two metals will help the manufacturer make the best choice for the application in question.
