The history of investment or lost-wax casting dates back thousands of years. Its earliest use was for idols, ornaments and jewelery, using natural beeswax for patterns, clay for the molds and manually operated bellows for stoking furnaces. Examples have been found across the world in India (2500–2000 BC), Egypt’s tombs of Tutankhamun (1333–1324 BC), Mesopotamia, Aztec and Mayan Mexico, and in Africa where the process produced detailed artwork of copper, bronze and gold.
The earliest known documentation that describes the investment casting process was written around 1100 A.D. by Theophilus Presbyter, a monk who described various manufacturing processes. This book was used by sculptor and goldsmith Benvenuto Cellini (1500–1571), who detailed in his autobiography the investment casting process he used for the Perseus with the Head of Medusa sculpture that stands in the Loggia dei Lanzi in Florence, Italy. The process is essentially the same today.
Investment casting came into use as a modern industrial process in the late 19th century, when dentists began using it to make crowns and inlays, as described by Dr. D. Philbrook of Council Bluffs, Iowa in 1897. Its use was accelerated by Dr. William H. Taggart of Chicago, whose 1907 paper described his development of a technique. He also formulated a wax pattern compound of excellent properties, developed an investment material, and invented an air-pressure casting machine.
In the 1940s, World War II increased the demand for precision net shape manufacturing and specialized alloys that could not be shaped by traditional methods, or that required too much machining. Industry turned to investment casting.
After the war, its use spread to many commercial and industrial applications that used complex metal parts.
Today, investment casting is a tried and true approach to manufacturing close tolerance and complex shaped parts. It has many advantages in modern metal manufacturing.