Metalworking And Metallurgy 101: Unique Metal Forming Processes

Some people think of metalworking as a simple skill, but metalworking is far more complicated than most people think it is. There are a lot of different metal working and casting processes, and each one is used for a variety of reasons. Some forms of metalworking involve intense heat, and others utilize relatively low temperatures to work metal. Some forms of metalworking are designed to work for tough metals and elements, are others are designed to successfully combine fragile metals together. Each facet of metalworking is unique in its own way, and if you're interested in metalworking and casting you may want to research these some of these fascinating methods.

Sand Casting/Sand Mold Casting

When people think of suitable materials to make molds out of, sand probably isn't the first material that comes to mind. Sand casting is a metal casting process that is characterized by using sand as the mold material. The sand used in the casting process is usually mixed with clay or another suitable bonding agent in order to make the sand mold suitable for metalworking. Sand castings are produced in specialized factors called foundries. It's also important to note that the term sand casting can also refer to an object produced via the sand casting process.

Extrusion

Extrusion is a process that is used to create object that have a fixed cross-sectional profile. Material (usually metal) is pushed or drawn through a die of the desired cross section shape. Some people choose to use the extrusion process for materials that are brittle since the material only encounters compressive and shear stresses that aren't powerful enough to compromise its structural integrity. Others use the extrusion process because it works well for materials that need to have very complex cross sections.

Powder Metallurgy

Did you know that you can make strong metals from powder? Powder metallurgy is the process of blending fine powdered materials, pressing them into a shape or form (this process is known as compacting), and heating the compressed material in a controlled atmosphere to bond the material together (this process is known as sintering). Compacting is usually performed at room temperature, and the elevated-temperature process of sintering is usually conducted at atmospheric pressure. The mass production of products made with powder metallurgy didn't occur until the 19th century, but crude forms of iron powder metallurgy and precious metal powder metallurgy were practiced by Egyptians and the Incas. The two main techniques people use to form and consolidate the powder are sintering and metal injection molding.

Cold Forming

Did you think that all metal working processes involved high heat? Cold forming is the metal working process of forging metals at near room temperatures. In the cold forming process, metal is formed at high speeds and pressures into tool steel or carbide dies. There are a variety of benefits that come with using the cold forming process. The process can be flexible. Parts can be hit several times while staying in a single die or transferred from several dies to progressively form a variety of geometries.

Editor's Note: Tony is a historian who likes to share information with people looking to learn about the origins of our modern technology.