In the production manufacturing, the analysis expression of the air hole of Ningbo laser cutting aluminum alloy casting parts are as follows:
Due to the unfavorable air oxidation breathing tendency of aluminum alloy profile, the furnace gas external air will be contacted immediately in the whole smelting process. Therefore, if the operation is slightly poor in the whole smelting process, the aluminum alloy profile will digest absorb the vapor easily produce blowholes, the most common is the pinhole.
Generally speaking, pinhole refers to the dissolved air holes less than mm in the casting parts, which are mostly round uneven distributed in all cross sections of the casting parts, especially in the thick cross-section the position with low cooling rate. According to the distribution appearance design characteristics of soluble air holes in aluminum alloy profiles, the pinholes can be divided into three categories.
1. Mesh structure pinholes: in the high-power mechanism, the needle holes are gathered connected to form a network structure. There are very few large holes in the metal pipe cutting. It is troublesome to check the total number of needle holes in the total area of the enterprise, the diameter size of the needle holes can be measured.
2. Speckled pinholes: in the high-power mechanism, the pinholes are small circles, their corridors are clear continuous with each other. The total number of pinholes per cubic centimeter of total area can be counted the diameter can be measured. This kind of needle eye is different shrinkage loosening.
3. Comprehensive type of air outlet: it is the middle type of spot shaped pinholes reticular needle holes. the perspective of high-power mechanism, there are many large pinholes, but they are small circles, but polygonal. According to the practice of aluminum alloy casting production, radon gas is the key vapor component of aluminum alloy profile which produces blowholes due to breathing, its emission has no certain regularity to be found. Generally, all most of aluminum alloy castings in a furnace have pinholes; the raw materials are listed, the aluminum alloy profiles with various components will cause pinholes.