Why do we need to degrease silicone precision casting?

The silica sol precision casting process often encounters the condition of air oxidation weld beading. The vast majority of this material is dispersed on the surface of the aluminum casting, and some of it is distributed on the corners that cannot be synchronized. If there are too many port numbers, it will appear yellowish or gray.

It can be seen from mechanical processing and manufacturing that the causes of these problems can also be found in pickling and passivation or acid treatment: the root cause is that the materials used in the furnace are not clean enough, and the amount of recycled materials is excessive; The design of gating system software is not very effective; The slag cleaning of aluminum alloy aqueous solution of silica sol precision casting mold is not clean enough, which may lead to the slag being brought when pouring due to actual operation non-compliance; Avoid for too long after metamorphic treatment.

In order to reasonably deal with this problem of casting, we must master the scientific and reasonable standard pouring rate, and try to reduce the amount of steam rolled in together; The core sand cannot be doped with macromolecular substances, which can reduce the gas generation of raw materials; Improve the surface arrangement of core sand to make casting stronger and stronger; At the same time, a better sprue should be used to improve the design of the gating control system.

Because of the low strength of aluminum alloy profiles, there is only a very thin dense layer on the surface during military silica sol precision casting, which is very easy to be destroyed. Therefore, it is proposed to use ultrasonic waves with high frequency and small amplitude during degreasing. The working frequency is generally 28-32KHZ, which is appropriate to prevent the dense layer of the workpiece from being damaged by excessive ultrasonic compressive strength. If the product workpiece is not polished and the appearance is simple, it is suggested not to use ultrasonic wave.

During casting, there are usually many sand holes on the surface, which is easy to cause hydrogen absorption problems. Therefore, it is proposed to add an anodic oxidation electrolysis method to remove oil during oil removal, try to remove the pollutants stored in the sand holes, and remove the residual radon gas, so as to enhance the bonding. The alloy materials applicable to electroplating process are only industrial pure aluminum and silicon containing aluminum magnesium alloy. Special attention must be paid to material selection and supervision of aluminum alloy profiles requiring electroplating process.