An integral aspect of metal production is the metal forming process, employed to reshape metals without removing material or altering its mass. The objective of metal forming is to take a raw metal piece and mold, configure, and transform it through tension, compression, shearing, and pressure.
Since the inception of the first industrial revolution, diverse metal forming methods have emerged. Metal forming typically commences with a sheet of plain flat metal subjected to various techniques such as forging, rolling, extrusion, drawing, stamping, and other methods. Each process is meticulously designed to yield durable metal products.
Metal forming encompasses two distinct methods: hot and cold. The cold process, also known as cold heading, occurs at room temperature or slightly above. This method involves a series of steps that gradually shape the workpiece to the required form using dies and hammers.
Die casting, a widely used method for shaping metals, involves heating metals to their melting point and pouring the molten metal into a mold. This process is predominantly executed with non-ferrous metals like copper, aluminum, zinc, magnesium, lead, tin, or bronze. Die casting is valued for the precision and extremely close tolerances it achieves in producing products and parts.
The expanded metal process, a form of cold metal forming, entails stretching and pulling metal, punctuating it with a blade to create shapes and designs. This method is cost-effective and applicable to aluminum, various steel types, and copper. Post-processing, finishes, and coatings can be added for protection or aesthetic appeal.
Forging, one of the oldest metal forming techniques, subjects a sheet of metal to stress to induce deformation, altering the grain flow and causing it to conform to the shape of the forging die. Falling between cold and hot forging, this process may involve heating the metal to facilitate forging without melting it.
Grey iron casting, distinct from forging, has been practiced for centuries, characterized by the gray color resulting from its graphite content. Various methods, including sand casting, are employed in the production of grey iron castings.
Investment casting is a process for producing multiple parts in one casting. It begins with creating a wax model of the part, which is converted into a mold and subsequently filled with molten metal to form the final part. Multiple molds are connected by a sprue, which is removed after the metal cools.
Metal spinning, a cold metal forming process, involves spinning a flat metal piece at high speed for shaping. Pressure is applied using various tools called spoons. The powder process of metal forming utilizes metal powder subjected to pressure in a die, interlocking particles to conform to the die’s shape. Sintering, heating just below the melting point, hardens the part and enhances its strength.
Roll forming, a cold process, guides a sheet of metal through rollers, gradually reshaping it into a uniform shape. This cost-effective method is applicable to metals like zinc, brass, steel, and aluminum.
Several other processes shape and form metals to produce common items like springs, wire forms, and wire mesh. These processes are predominantly cold forming, with some methods involving heating metals for increased pliability.
