1 Overview

Dongguan Precision CastingAlso known as&"dewaxed casting GG", usually the wax pattern is coated with several layers of refractory material, and after it is hardened and dried, the wax pattern is melted to form a shell, and then it is baked, but it is left behind. It is also called&"Investment Precision Casting GG" due to the high dimensional accuracy and roughness of the obtained castings.

The process of precision casting. The types of alloys that can be produced by precision casting include carbon steel, alloy steel, heat-resistant alloys, stainless steel, precision alloys, permanent magnet alloys, bearing alloys, copper alloys, aluminum alloys, titanium alloys, and ductile iron.

The shapes of wax mold castings are individually complicated. The minimum diameter of the holes that can be cast on the castings can reach 0.5mm, and the minimum wall thickness of the castings is 0.3mm. In production, some parts can be assembled from several parts from the original source. The structure of the parts is transformed through the process, and the parts are designed as integral parts and directly cast by precision casting. This saves the processing time and the waste of metal materials to make the parts The structure is double fair.

The weight of investment castings is mostly zero tens of cattle (that is, tens of grams to several kilograms). It is more troublesome to produce heavy castings by precision casting, but the weight of producing large investment castings has reached 800 cattle.

Precision cast steelThe process is more complicated, and it is not easy to control, and the materials for operation and consumption are more expensive. Therefore, it is suitable for the production of small parts with complex shapes, high precision requirements, or difficult to perform other processing, such as the blades of turbomachines.

Stainless steel finely forged refractory coating is a suspension made of powdered refractory materials (silica powder, corundum powder) and ethyl silicate hydrolysate, or water glass solution. The coating is different according to the shell level, which can be divided into the surface layer and the reinforcement layer (that is, the second layer and subsequent layers).

Lost wax castingThe surface layer coating determines the surface quality of the casting, so it is requested that the coating quality be high, the silica powder should be fine, the viscosity of the coating should not be too high, and the sand removal should be finer. The reinforcement layer paint has a strengthening effect on the shell and avoids damage to the shell. Therefore, coarser silica powder can be used, the viscosity of the coating is higher, and the particle size of sand removal is also larger.

Manufacturing method: First, put the dry material into the mixing barrel according to the quantitative amount, and continue to mix it. Continuously add powdered information. After the addition, continue mixing for more than 15 minutes, and stop until the powdery material becomes a uniform suspension. It can be used after standing for a period of time.