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Shortly after the dark ages in Europe, the industrious sculptor and goldsmith, Benvenuto Cellini began to make use of the lost wax method of casting. He learned this process from the writings of the monk Theophilus Presbyter (circa 1100) whose Schedula Diversarum Artium is the earliest known foundry text. In Cellini's autobiography, considered to be one of the classics of literature, he describes in great detail the casting of his famous Perseus and the Head of Medusa. This three and a half ton statue was completed in 1554 and was unveiled at the Loggia dei Lanzi in Florence, Italy, where it stands to this day.
During World War II, with urgent military demands overtaxing the machine tool industry, the art of investment casting provided a shortcut for producing near net shape precision parts and allowed the use of specialized alloys which could not be readily shaped by alternative methods. The investment casting process was found practical for many wartime needs--and during the postwar period it expanded into many commercial and industrial applications where complex metal parts were needed. It was in this period that the Hitchiner Manufacturing Company was founded at the Amoskeag Millyards of Manchester, NH.
The solid mold technique was first utilized because a technology to successfully remove the wax patterns from a shell without causing it to collapse, crack or burst had not yet been devised. In the solid mold technique, a wax sprue was placed in a steel casing and surrounded by a setting slurry. The drawbacks of the solid mold technique were extremely long pre-heat, size limitations and poor dimensional tolerances.
Over 4,000 years ago, between the Tigrus and Euphrates Rivers in a land known as Mesopotamia, ancient artisans produced idols and ornaments using natural beeswax for patterns, clay for molds and manually operated bellows for stoking furnaces. Today, precision components for spacecraft and jet engines are investment cast using the latest advances in computer technology, robotics and countergravity casting techniques. |