Common Defects in Copper Casting
The metal casting process has changed little in the thousands of years since its original invention. Today’s copper casting companies have invented new machines and casting materials that make the process easier and defects less likely, but in the end, the overall casting process remains the same. First, the copper is melted, then poured into a mold and allowed to harden. After the metal hardens, it is removed from the mold and polished and modified until it reaches the desired shape, texture, and brightness.
In copper casting, some defects are normal and can occur even in the most precise machines and with the most talented operators. Here are some of the most common defects you may find copper casting companies make during the casting process:
Porosity: This defect occurs when bubbles form on the metal after it cools. It is possible to prevent this defect by melting the copper in a vacuum or by keeping melting temperatures as low as possible.
Shrinking: Shrinking naturally occurs as the metal hardens. However, defects occur when the metal shrinks unevenly. This often occurs when the cast is unevenly heated, or has hot or cold spots on the mold. This can be prevented by ensuring the mold and metal retain an even heat and cool evenly until the metal is solid.
Mold defects: These defects occur due to problems with the mold. This can happen if the metal does not fill the mold properly, or if metal does not fuse together. If the mold itself has cracks or other problems it will also cause defects. Usually, it is possible to fix this problem by ensuring the mold is stable and that the metal is poured evenly into the mold.
Metallurgical defects: These defects occur with cracks due to uneven heating or spots of metal that are much harder than the rest due to uneven cooling. Keeping the mold at an even temperature can eliminate these defects.