To begin, the casting crucible is furnace-fed by an under-pouring method from a continuous melting source. The molten metal is maintained at the correct holding temperature in the crucible, which is completely enclosed. Any dirt, dross or gases present rise to the top of the melt and are left behind in the casting process. Acting as a riser, the metal prevents the formation of shrinkage cavities that would otherwise introduce imperfections in the final product.
CASTING IS KEY
Through decades of experience, Concast has proven that superior products are created through vertical or horizontal continuous casting methods. The preferred casting technique is determined by the alloy and by the size range being produced.
Vertical continuous casting has been the strength of Concast's production for over a third of a century. As the metal flows down into a water-cooled die at the bottom of the crucible during vertical continuous casting, solidification of the alloy occurs. The cast product continues smoothly downward through rollers beneath the die. With precise temperature control, the rollers carefully withdraw the cast metal to determine its grain structure and metallurgical properties.
Horizontal continuous casting is best suited for aluminum bronzes due to the material's metallurgy. As a result, our Birmingham plant has been dedicated almost exclusively to the production of aluminum bronze. During horizontal continuous casting, metal flows out the front of the crucible and into a water-cooled die where solidification takes place. Drive rollers pull the bar along roller tables that support the weight of the bar while it casts. With precise control of temperature, the desired grain structure and metallurgical properties are created.
The manufacturing of our products is a precisely timed process. A traveling saw, synchronized with the ongoing continuous casting, automatically cuts the bar to a uniform length for delivery to the cooling rack and then to inventory. Custom lengths can be cut from stock. Because straightness is a critical requirement for continuous cast bronze, all of our bars are Medart® straightened.