Process of Precision Casting

2022-06-21

Precision casting is a generic term for the process of obtaining castings of precise dimensions. Compared with the traditional sand casting process, the casting size obtained by precision casting is more accurate and the surface finish is better.  It includes investment casting, ceramic mold casting, metal mold casting, pressure casting, lost foam casting.

One of the more commonly used is investment casting, which is also known as lost wax casting, its process is as follows: Select suitable investment material (such as paraffin) to make investment mold; Repeat the process of coating and spraying refractory sand on the investment mold, hardening the shell and drying; Then the internal investment mold is dissolved to obtain the cavity; Bake the shell to obtain sufficient strength and burn off the residual investment material; Pour the needed metallic material; Solidify and cool, remove sand after peeling. In this way, the finished product can be obtained with high precision. According to the needs of the product, heat treatment and cold work and surface treatment are also performed.

 Process

 Wax pressing(making wax mold by injection) ---fix wax----wax test----tuple tree（wax tuple tree）---shell-making（First moistening slurry, then surlyen, moistening slurry again, finally mold air dry）---dewaxing（steam dewaxing）-------mold baking--chemical analysis--pouring（Pour molten steel into the mold）----decorticate by vibration---cutting and separating of casting and -gate stick---sprue grinding ---initial check（casting check）---impact cleaning-----machining-----polishing---finished product check---storage

The casting production process is basically as described above. Generally speaking, it can be divided into wax pressing, shell making, pouring, post-treatment and checkup.

Wax pressing includes（wax pressing, fix wax, tuple tree）

Wax pressing---Wax mould is made by wax injector press

Fix wax---Make corrections to wax molds

Tuple tree---Make tuple tree for the wax mold

Shell-making includes（Hang sand, hang slurry, air dry)

Pouring includes（Baking, chemical analysis which is also known as spectrum, pouring, decorticate by vibration, cutting sprue, sprue grinding）

Post-processing includes（Sandblasting, shot blasting, correction, pickling）

Checkup includes (wax checkup, initial checkup, in process checkup, finished product checkup)