Identify good and bad aluminum castings

Identify good and bad aluminum castings

Aluminum casting often encounters the problem of oxidation slag inclusion, these substances are mainly dispersed on the surface of aluminum castings, and some are even distributed in hard-to-reach corners, which will cause some areas to appear yellow or gray. After mechanical processing, this situation is more obvious, and in pickling or alkali washing, we can find the reason why this phenomenon occurs.

First of all, the cleanliness of raw materials in the furnace is not enough, and the use of return charge is too much; Secondly, the design of pouring system is not reasonable enough; In addition, the slag in the aluminum casting alloy solution is not cleaned thoroughly, and the slag may be brought into the casting process due to irregular operation; Finally, too long deterioration processing times can also cause such problems.

In order to effectively solve these problems, we need to grasp a reasonable pouring speed and try to avoid the gas involved; Organic matter should not be mixed into the core sand to reduce the amount of gas released by the material; Improving the discharge function of core sand makes aluminum casting more powerful; In addition, choosing the appropriate cold iron and improving the defects of the gating system design can solve the above problems.