Investment casting, often called lost wax process casting, is regarded as a precision casting process to fabricate near net-shaped metal parts from almost any alloy and is typically used for the production of components requiring complex, often thin-wall castings.
There is a long and rich history associated with investment casting, dating back thousands of years to the production of bronze, copper and gold jewelry, idols and statues as far back as the ancient Egypt and Mesopotamia, the Han Dynasty in China, the Aztecs in Mexico and the Benin civilization in Africa. The earliest known text describing the investment casting process was written by the monk Theophilius Presbyter around 1100 A.D. His writings were used by sculptor and goldsmith Benvenuto Cellini (1500 – 1571), as described in his autobiography, for the production of the Perseus and Head of Medusa sculpture that still stands today in Loggia dei Lanzi in Florence, Italy. In fact, by the mid 1500′s the investment casting technique was considered “ordinary procedure” for making bronze statues and other works of art.
The technique reemerged in the late 19th century when dentists began using the technique to make crowns and inlays, following the publication of a paper by Dr. D. Philbrook of Council Bluffs, Iowa in 1897. It was Dr. William H. Taggers of Chicago, however, who spearheaded the use and growth of investment casting as a modern industrial process, following publication of a paper in 1907 that detailed the development of a technique that utilized a wax pattern compound of excellent properties, the development of an investment material and the invention of an air-pressure casting machine.
Use of investment casting accelerated significantly during the 1940′s as a result of military demands on the machine tool industry. Investment casting proved to be an efficient, reliable and cost-effective method for meeting military demands for near net-shape precision parts and use of specialized alloys that could not be shaped by traditional methods, or required too much machining. Following the war, the technique expanded into many commercial and industrial applications that used complex metal parts. It was during this time that Bimac emerged and ultimately evolved into one of the leading investment casting providers in the Midwest.