User:MattTimme80/sandbox

History of Green Sand Casting

"Although history does not record when or where the first metal casting was made or who produced it, artifacts and Biblical references indicate this probably occurred in ancient Mesopotamia about 5000 to 6000 years ago. The oldest casting in existence is believed to be a copper frog cast in Mesopotamia about 3200 B.C., and its complexity indicates that the artisans of that time had already developed considerable expertise in the art and science of metal-casting. Early historical information on metal-casting is difficult to find for two major reasons. First, the production of metal castings predates writing; thus there is little written record of the early events. Second, few metal artifacts exist since these were quite precious and the metal could be easily remelted and recast into other useful objects. You might say that metal-casters were the first to practice recycling.

Man learned to improve the properties of castings through alloying. Bronze (copper-tin) castings began to appear about 3000 B.C. The first production of iron castings is attributed to the Chinese about 1000 B.C. Cast-crucible steel was made in India about 500 B.C., but the process was lost and not rediscovered until the late 1800s. Sir Humphrey Davy of Great Britain discovered the existence of aluminum in 1808, and, by 1884, the total U.S. production of aluminum was a mere 125 pounds per year. In 2013, the United States produced 8.4 million metric tons of gray and ductile iron castings, 1.4 million metric tons of steel castings, 1.7 million metric tons of aluminum castings, and 321 thousand metric tons of copper-base castings."

New Progress/Overview

Newly developed casting processes have revolutionized the casting industry allowing metal-casting technology to advance further in the last 50 years than in the previous 5500 years. This astounding progress—achieving better cast surfaces, closer dimension tolerances, and faster turnaround times—has been primarily due to the ingenuity of the many developers of new processes as well as the application of modern scientific instrumentation to probe the science of sand technology, metallurgy, and metal solidification.

The metal-casting process consists of pouring molten metal into a mold containing a cavity of the desired shape of the casting, and allowing the metal to solidify. There are many processes used to make metal castings. What differentiates one process from another is the material from which the mold is made, the type of pattern used (permanent or expendable), and the amount of pressure, or force (positive or negative), that is used to fill the mold cavity with molten metal. Conventional green sand, chemically bonded, V-process, and plaster molds utilize permanent patterns, but the mold is used only once. Permanent mold and die-casting molds are machined in metal or graphite, often called a die, and can be used repeatedly. Investment casting and the lost foam process involve an expendable pattern as well as an expendable mold."

Sand Components(NEEDS MORE)

The casting of metals has been practised for approximately 5,000 years using first gold, copper, and bronze, then iron, and now alloys of zinc and other metals. The traditional method of casting metal is sand casting. Using a model of the object to be produced, a hollow mould is made in a damp sand and clay mix. Molten metal is then poured into the mould, taking its shape when it cools and solidifies. The sand mould is broken to release the casting. Permanent metal moulds called dies are also used for casting, in particular, small items in mass-production processes where molten metal is injected under pressure into cooled dies. Continuous casting is a method of shaping bars and slabs that involves pouring molten metal into a hollow, water-cooled mould of the desired cross section.