Casting method of bronze sword

Zhu introduced that the die casting method is also called die casting method. First, clay molds are used to carve various patterns and inscriptions, which are dried in the shade and then fired to make the master mold. Then the clay model is made with the master mold, and the ceramic model is also made in the shade, melting the alloy, and pouring the alloy into the cavity of the ceramic model to make the bronze finished product.

According to the objects excavated from the ruins of ancient bronze workshops and the shape analysis of bronze swords, experts believe that most ancient bronze swords in China are made by paradigm casting. The technological process of bronze sword model casting method is divided into five steps: the first step is to mold the basic shape of bronze sword with soil. Draw the outline of bronze sword pattern on the prepared clay mold, the concave part is directly carved from the clay mold, and the convex part is separately prepared and pasted on the surface of the clay mold; The second step is to turn over the fan, that is, the fine mud mixed evenly in advance is tightly pressed on the surface of the clay mold, and the shape and ornamentation of the clay mold are printed on the clay piece after flapping; The third step is to combine the mud blocks, divide them into several pieces, and then burn them into pottery. This kind of clay is hard and not easy to deform, so it is called pottery. Pottery models are assembled to form the outer cavity of the object, which is called the outer mold. After the outer mold is made, a thin layer of clay mold for turning over the mold is cut off evenly to make the inner surface of the object, which is called the inner mold, and the inscription of bronze sword is engraved on the inner mold. Connecting the inner and outer templates into a whole, the gap cut between the inner and outer templates is the place where the copper liquid remains, and the distance between them is the thickness of the bronze sword; The fourth step is pouring, in which the copper liquid is poured into the ceramic mold. After the copper liquid solidifies, break the inner and outer ceramic molds and take out the cast copper sword. A set of pottery models can only cast one bronze sword, and it is impossible to have two identical bronze swords; The fifth step is to polish and renovate. The newly cast bronze sword has rough surface and unclear pattern, which needs polishing and renovation to become a delicate bronze sword.