Lost-Wax Method

Lost-Wax Method

 

a method for the production of shaped castings from metal alloys in a one-piece hot shell mold that does not evolve gases. The cavity of such a mold is generated through removal of the casting pattern by burning, melting, or dissolution.

In the lost-wax method, a pattern composition is pressed into a mold (usually a metal mold), forming the casting pattern and the gating. The pattern composition is removed, most frequently by melting it with hot water. The resulting shells are calcined at 800°-1000°C and then filled with metal.

The lost-wax method makes possible the casting of articles of complex shape weighing a few grams to several dozen kilograms. The castings have wall thicknesses of 0.5 mm or more, a surface roughness corresponding to the fourth to sixth classes of the Soviet standard, and higher dimensional precision than in other casting methods. These characteristics were the basis for the previous name of the method, “precision casting.” The dimensions of castings produced by the lost-wax process are very close to the dimensions of the finished part, which leads to a decrease in cost through reduction of mechanical treatment.

The lost-wax method is used to produce cast objets d’art, jewelry, and dental prostheses. One of the oldest casting methods, it has become widely used as a result of improvements in casting technology and studies of the properties of organosilicon compounds.

Casting by the lost-wax method is concentrated in the USSR in highly mechanized foundries, which produce up to 2,500 tons of finished castings per year. One of the achievements of Soviet industry is the creation of fully automated processes of lost-wax casting production.

V. N. IVANOV

References in periodicals archive ?
Bronze pendants, torcs, bracelets and finger rings from West Africa, made through a lost-wax method dating back to the 15th century, are also sought-after.
After those were approved, the next step was to mold and cast the figures in bronze, using the lost-wax method.
The most celebrated aspect of these bronzes is the process through which they are made, the cire perdue or the lost-wax method (figure 3).
Packed with medieval bronzes from the ground to the second floor, the informational posters introducing the visitor to the gallery describe the lost-wax method used by sculptors to make these bronzes as one that harks back to the Indus civilization (figure 4).
Last week, the academy announced it had retained the firm of Polich Tallix to resurrect Gibbons' original 1920s design and again cast the statues in solid bronze via the lost-wax method. It's a process so painstaking that the New York foundry is taking three weeks just to make 50 statues.
Referring to a special diagram with samples from the steps of the process, Winn then delivered an engaging and informative overview of the lost-wax method, an expensive, arduous process that is thousands of years old.
From this act of removal he generated another form, casting the torn-off corner in zinc, using the traditional lost-wax method. Now the missing portion, transformed, lies as an addition in front of the ripped-open wall.
Now it seems established that while later forgers employed the lost-wax method of casting, the Western Zhou bronzes were cast in sectional molds which required the positioning of spacers within, or near, the area of the inscription.
Each is cast using the traditional lost-wax method by Europe's largest sculpture foundry, Pangolin Editions.