Bubbles usually appear in defects in silica sol precision casting, referring to lubrication hole plate defects in individual positions of precision castings. Bubbles are usually discovered after processing. Our precision casting technicians have many years of workshop consumption experience, and the causes and prevention of bubbles in precision casting are summarized as follows:

1、 Cause of formation:

1. Bubbles are mostly caused by insufficient roasting of the precision casting shell. When molten steel is injected into the shell, a large amount of gas cannot be discharged smoothly, thus invading the liquid metal to form bubbles;

2. Due to the poor permeability of the shell during the shell making process or the type of shell data, it is difficult to expel gas from the cavity, which enters the metal liquid and forms bubbles;

During the pouring process, when the air in the steel is not discharged, casting bubbles will form.

2. Preventive measures

1. Install exhaust bubbles above structurally complex castings, provided they meet the conditions for precision casting.

When designing the pouring system, the exhaust requirements of the shell should be fully considered.

3. The roasting temperature and time of the shell should be reasonable, and the insulation time should be sufficient.

4. When dewaxing, the wax should be thoroughly cleaned.

5. Properly reduce the distance between the ladle nozzles and the pouring cup, average the pouring speed, ensure stable steel level, fill the cavity, and minimize air entrainment into the steel liquid. This way, the air cavity and steel liquid can be discharged smoothly.

Dongguan Fengzhuo Hardware Products Co., Ltd. is composed of a precision casting factory and a mold design and processing factory. The company undertakes casting drawing and sample processing through OEM, and can cooperate with other partners to provide a one-stop service from product precision casting drawing design, mold making, casting blanks to machining and polishing. To meet customer needs with excellent quality and excellent service, and establish good partnerships with customers.