Precision casting refers to the general term for the process of obtaining precise size castings. Compared with the traditional sand casting process, the castings obtained by precision casting are more accurate in size and have better surface finish. Precision casting includes: investment casting, ceramic casting, metal casting, pressure casting, lost foam casting.
Precision casting is also called lost wax casting. Its products are precise, complex, and close to the final shape of the part. It can be used directly without processing or a small amount of processing. It is an advanced process with near-net shape.
Precision casting includes: investment casting, ceramic casting, metal casting, pressure casting, lost foam casting.
Among them, investment casting, also known as lost wax casting, is more commonly used: select suitable investment materials (such as paraffin) to make investment; repeat the process of dipping refractory paint and spreading refractory sand on the investment, hardening the shell and drying; Melt the internal investment mold to obtain the cavity; bake the shell to obtain sufficient strength and burn off the remaining investment material; pour the required metal material; solidify and cool, and remove the sand after shelling, so as to obtain high Precision finished product.
What kind of development has precision casting experienced?
Ancient China: Prince Wuding, Bronze Ban, Bronze Lion, etc. are all masterpieces of investment casting. Since investment casting was used in industrial production in the 1940s, it has been developing at a rapid rate for half a century. In particular, European and American countries are developing rapidly. Investment casting is used in almost all industrial sectors, especially in electronics, petroleum, chemical, energy, transportation, light industry, textiles, pharmaceuticals, medical equipment, pumps and valves. China has also developed rapidly in recent years.
The development of investment technology enables investment casting not only to produce small castings, but also to produce larger castings. The outline size of the largest investment casting is nearly 2m, while the minimum wall thickness is less than 2mm. At the same time, investment castings are also becoming more precise. In addition to linear tolerances, parts can also achieve higher geometric tolerances. The surface roughness of investment castings is also getting smaller and smaller, which can reach Ra0.4μm.
What is the process of precision casting?
1. Wax pressing (wax injection to make wax mold)---wax repair---wax inspection---group tree (wax module tree)
2. Shell making (first dip, sand, then dip, and finally the mold shell air-drying)---dewaxing (steam dewaxing)-------mold shell roasting--chemical analysis
3. Pouring (pouring molten steel in the mold shell)----vibration shelling----casting and casting rod cutting and separation----grinding gate
4. Initial inspection (raw embryo inspection) --- shot blasting cleaning --- machining --- polishing --- finished product inspection --- storage
The production process of precision casting is generally like this. Generally speaking, it can be divided into wax pressing, shell making, pouring, post-processing and inspection.
Press wax includes (press wax, trim wax, tree group)
Wax pressing is to use a wax pressing machine to make wax molds;
Wax repair is to correct the wax mold;
The group tree is to group the wax mold into a tree;
Shell making includes (sand hanging, pulp hanging, air-drying)
Pouring includes (roasting, chemical analysis also called spectrum, pouring, shell shock, gate cutting, gate grinding)
Post-processing includes (sand blasting, shot blasting, correction, pickling)
Inspection includes (wax inspection, initial inspection, intermediate inspection, finished product inspection)
The above is the development history of precision casting and its technological process organized by PARFECT for you. If you are interested, you can continue to pay attention to us.
