Cast aluminum alloys introduction
The density of cast aluminum alloy is lower than cast iron and cast steel, while the specific strength is higher.Therefore, under the same load conditions using aluminum alloy castings, can reduce the weight of the structure. It is in the aviation industry and power machinery and transport machinery manufacturing, aluminum alloy castings are widely used. Aluminum has a good surface gloss, in the atmosphere and fresh water has good corrosion resistance. it has a wide range of uses in the manufacture of civilian vessels. Pure aluminum in nitric acid and acetic acid and other oxidizing acid medium has good corrosion resistance, and therefore aluminum casting in the chemical industry also has some uses.Pure aluminum and aluminum alloy have good thermal conductivity, on the heat exchange devices used in chemical production, as well as the parts on the power machinery that require good thermal conductivity, such as the cylinder head and piston of the internal combustion engine. And it is also suitable for use with aluminum alloy manufacture.
Technical key points
u Take effective measures to reduce the casting temperature to eliminate crack defects, at the same time reducing the temperature drop of molten steel to ensure the filling capacity of steel. Main technical measures: one is to directly reduce the casting temperature, the original pouring temperature of 1600 ℃ -1610 ℃, and now strictly control the temperature at 1570℃ -1580 ℃. Second, to reduce the temperature drop of molten steel. After the mold are assembled, blow heat wind 150 ℃ -200 ℃ to the cavities for 60 min-90min, and stop blowing 5min before pouring.
u Pouring should be fast, first calculate the pouring time, apply plunger type leakage bag to pour in stipulated time.