Under normal pressure, the factors that can increase the gas content in the metal and hinder the escape of bubbles from the surface can make the aluminum alloy wheels appear pores. There are also many reasons for the occurrence of pores. The following are the reasons that steel casting manufacturers briefly summarize for everyone:
1. Reasons for the structure of aluminum alloy wheels: relatively large flat aluminum alloy wheels will be in a horizontal position when pouring. When the bubbles floating in the liquid metal reach the plane, it is generally impossible to float because there are no flat bubbles. If the surface is solidified or Air bubbles cannot escape through the core wall, and pores will be generated; when the wall of the aluminum alloy wheel is thin, the pouring speed is too fast, and the gas pressure causes boiling; the radius of the rounded corner of the aluminum alloy wheel is too large Small, it is easy to produce concave angle pores.
2. Reasons for smelting: The quality of the metal charge is low, the surface has been severely oxidized, and it is also oily, porous, with more impurities, and thinner, which will cause the molten metal gas and metal oxide content to be excessive Too many, resulting in the appearance of gas holes in the aluminum alloy wheel hub; the charge is wet; the size of the metal charge is too small or too loose; the deoxidation is not complete in the metallurgical process, or the amount added is insufficient, and the floating part of the liquid enters the slag, resulting in the actual aluminum used for deoxidation Insufficient amount; improper smelting temperature control; insufficient drying of furnace wall, iron removal trough, and ladle; improper control of slag and actual smelting length; unqualified liquid chemical composition.
3. Reasons for the design of the process: improper design of the core head; too large gap between the core head and liquid inflow will easily block the vent; the height of the flask is too low and the static pressure is low; the pouring system will be formed or incorrectly selected; the position of the inner gate Unreasonable; poor exhaust of the cavity, too few risers, too few vents, etc.Article from www.jihoowheels.com
