The aluminum ingot continuous casting machine is a highly efficient and automated equipment widely used in the scrap aluminum recycling industry.
During the aluminum ingot casting process, ripples of varying degrees will form on the surface of the ingot during solidification.
Severe ripples can affect the appearance quality, thereby impacting the selling price. Products with severe ripples are usually rejected, forcing manufacturers to send them back to the furnace for remelting, resulting in significant economic losses and seriously affecting the manufacturer's reputation.
Therefore, it is necessary to thoroughly study the causes and solutions of surface ripples on aluminum ingots.
Common ripples on the surface of aluminum ingots include concentric circles, bubbles, and grooves at both ends.
Concentric water ripples refer to the ripples formed on the surface of the aluminum ingot mold after the aluminum liquid enters the mold through the distributor and cools and solidifies.
It originates from a point on the surface of the ingot and spreads in a ripple pattern in all directions. This type of ripple is caused by the high-temperature aluminum liquid oxidizing in the air as it flows into the casting mold, generating a large amount of oxide film slag.
When the slag is removed, the aluminum slag is cleared from the mold, stirring the aluminum liquid in the mold and disturbing the surface of the aluminum liquid, resulting in concentric ripples during solidification.
During the cooling process of the aluminum liquid in the mold, vibrations of the mold caused ripples with grooves at both ends on the surface of the formed aluminum ingot.
These ripples take the shape of deep grooves on the surface of the aluminum ingot, with the middle being the deepest and the ends being shallower. These water ripples have the greatest impact on the appearance quality of the aluminum ingot, with the largest amplitude.
The formation of these ripples is due to the polygonal movement of the chain in the transmission, periodic fluctuations in chain speed and instantaneous transmission ratio leading to unstable transmission.
At the same time, the relative speed between the chain links and gear teeth during engagement can also cause vibration of the ingot mold. The vibration of the ingot mold causes the aluminum liquid to shake.
Due to the lower temperature near the inner wall of the crystallizer, the aluminum liquid at this position solidifies first, and the vibration peak of the un-solidified aluminum liquid near the already solidified aluminum liquid solidifies each time it approaches, forming deep grooves in the aluminum ingot with the middle part as the boundary.
To address these ripple issues, the following improvement measures can be taken:
Improvement measures for concentric ripples:
- Strengthen the refining of the aluminum liquid in the insulation furnace to ensure a clean and thorough slag removal process, reducing the impact on subsequent slag removal.
- Minimize the length of the launder to reduce the contact time of the aluminum liquid with air during the flow process, thereby reducing the formation of oxidation slag on the surface.
Improvement measures for bubble water ripples:
- Strictly control the quality of the aluminum ingot casting mold.