Precision casting aluminum die castings can be made into blanks with complex shapes and very complex inner cavities, such as casings, cylinder liners, etc. Integrate into a wide range. Forging allows immediate use of cost-effective scrap parts and drilling with low mechanical equipment costs. The specifications and quality of castings are mostly unlimited. The appearance, specifications and models of castings are very close to the parts, thus reducing the workload of drilling and manufacturing, and saving a lot of metal materials and polymer materials.
The disadvantage of precision castings is that the production process is various, the whole process of the production process is difficult to control, and the castings are easy to cause defects. The specifications and models of castings have poor uniformity and low accuracy. Compared with stainless steel castings of the same shape and size, the actual quality of infrared carbon sulfur meter castings is poor, and the bearing capacity is not comparable to stainless steel castings. The working environment is poor, the temperature is high, the dust is high, and the labor productivity is high.
After the outer contour of the aluminum die-casting part is finished, there should be no casting defects such as blowholes. Sand (slag) eyes appear uneven small gaps on the surface of the casting, which are generally uneven, with different depths, and the interior is uneven, and there is no cold mouth. It is mainly because the converter is dirty, the welding tumor penetrates during pouring, and the sand is shoveled when the debris removal sheet is released.
The small stones remaining in the metal mold are rushed into the concave mold with the converter. When clamping the mold, the middle of the metal mold or the middle of the metal mold and the sand core is extruded, causing small stones to fall down. Metal mold casting sand has poor characteristics (such as low moisture content and poor tensile strength). When the scheme is designed, too fast water seepage will easily cause sand flushing. The main reason is that the gravel in the die is not quiet. Before pouring, the gravel had penetrated from the widening opening such as the sprue or gate. The tensile strength of the sand mold is not enough, and the external force causes it to fall down.
The continuous pouring or the slow pouring speed causes the gravel in the die to not be completely suspended on the gate, and stay in the area with lower temperature.
A layer of oxide skin is caused on the outer layer of stainless steel sheet castings, also known as skin darkening. It can be removed by sandblasting, and of course, it can also be removed by mechanical processing. Inconvenient and fast areas can be removed by phosphating. After there is this layer of oxide skin, because this layer of oxide skin may fall off, the appearance becomes more and more unsightly, and it is not easy to take corrosion-resistant precautions such as paint and electroplating. It should be said that there is no back effect of much money.