Several major issues to pay attention to when storing copper castings
1. When storing copper castings, it is necessary to place them in a ventilated, dry, and corrosion-free inventory environment; Strictly prevent rainwater from getting wet.
2. Copper castings must not come into contact with other chemical elements. When copper castings come into contact with other chemical elements, the chemical elements will react with the copper castings, causing damage to the copper castings.
3. If the raw material alloy ingot for casting zinc alloy products is affected by moisture, it should be dried before adding to avoid “shooting” or damaging equipment during melting.
4. Each copper casting has its own shape. When placing zinc alloy copper casting products, it is important to customize a good suction cup according to the shape of each copper casting product. This allows the copper casting to be placed in the correct position, ensuring that the copper casting is intact and does not undergo any other changes.
5. Zinc is a reactive metal that is prone to oxidation when exposed to certain temperatures. Therefore, when storing zinc alloy copper castings, we should pay attention to the temperature and avoid direct sunlight.
Requirements for design ribs of copper castings:
The function of the reinforcement is to improve the strength and rigidity of the parts after the wall thickness is thinned, prevent the reduction of shrinkage deformation of the copper casting, and avoid deformation of the workpiece when it is ejected from the mold. When filling, it is used to act as an auxiliary circuit (a passage for metal flow). The thickness of the copper casting reinforcement should be less than the thickness of the wall where it is located, usually 2/3~3/4 of the thickness at that location.
Copper castings are also closely related to daily life. For example, commonly used doorknobs, door locks, radiators, plumbing pipes, iron pots, gas stoves, irons, etc. are all castings. Among them, ordinary sand castings are widely used, accounting for about 80% of the total casting production. Non ferrous metal castings such as aluminum, magnesium, and zinc are mostly die castings. The weight of copper castings accounts for a large proportion, and many structural components and major components are made of castings as raw materials, which are closely related to the quality and accuracy of the machine tool. The quality of machine tool castings has a significant impact on the overall quality, lifespan, and accuracy retention of the machine tool.
Many structural components and main components of copper castings are made from castings, which are closely related to the quality and accuracy of copper. The quality of copper castings has a significant impact on the overall quality, lifespan, and accuracy of machine tools. Copper castings can also be used in valves, speakers, injection molding machines, water supply and drainage pipelines, etc.
There are various classification methods for castings: according to the different metal materials used, they are divided into steel castings, cast iron castings, aluminum castings, copper castings, copper castings, etc. And each type of casting can be further divided into different varieties based on its chemical composition or metallographic structure. Iron castings can be divided into gray iron castings, malleable iron castings, alloy iron castings, etc; According to different molding methods, castings can be divided into ordinary sand castings, metal castings, die castings, ceramic castings, electroslag remelting castings, bimetallic castings, etc. Among them, ordinary sand castings are widely used, accounting for about 80% of the total casting production. Non ferrous metal castings such as aluminum, magnesium, and zinc are mostly die castings.
The concave areas on the surface of copper castings are called depressions, which can be caused by:
1. In situations where the performance of the machine’s injection mechanism is poor (such as in old vertical machines), when the working fluid pressure is unstable, the injection pressure is also unstable. The pressure pushing the metal is discontinuous, causing the skin layer of the copper casting to form more than once, but the edge position of the skin layer is different each time. Some edges of the previous skin layer are not covered by the latter, resulting in strip shaped depressions.
2. During filling, the gas is squeezed between the metal flow and the cavity wall without being expelled, resulting in a depression. The surface of this depression is smooth and clean, often appearing in the difficult to exhaust cavity, while copper castings are on the edge of the end.
3. The hot spot area of copper castings is filled with voids inside. When shrinkage occurs, although the skin layer has strength, it is still affected by internal shrinkage and the surface appears concave, which is called shrinkage.
4. There is residue in the mold cavity, which has been mentioned earlier in the cause of undercasting. But when it occurs, the residue in the mold cavity is not in the form of a sheet, but with various irregular shapes. The height of the residue above the mold surface is not high, so the copper casting is also relatively shallow.
Post time: Aug-30-2023