In the copper casting process should pay attention to those things?

Copper casting casting process, strict control of all steps and key parameters to ensure the quality of castings is critical. 

The following are the matters that need special attention in the casting process:

Copper liquid temperature: the melting point of copper is between 1000°C and 1100°C, the casting should ensure that the molten copperliquid temperature is appropriate. Too high a temperature will lead to too much oxidation, increase the copper casting of porosity and shrinkage defects; too low a temperature will lead to poor fluidity of the copper liquid, filling the mold is not sufficient, easy to produce cold segregation and shrinkage holes.

Uniform heating: The copper liquid must be heated uniformly to avoid localized overheating or cold zones. Use stirring or heating equipment to ensure that the temperature of the liquid copper is consistent throughout.

Gas Influence: Copper liquid easily absorbs oxygen and hydrogen in the air during the melting process, forming porosity and affecting the denseness and strength of copper castings. Therefore, degassing is required before casting.

Degassing method: commonly used inert gas (such as argon, nitrogen) for degassing, or add degassing agent to remove the dissolved gas in the copper liquid.

Mold temperature control: mold preheating to the appropriate temperature (such as 200 ° C to 300 ° C), can effectively reduce the copper liquid cooling too fast, to avoid the production of thermal cracks and copper castings surface defects.

Uniform preheating: Especially for metal molds, it is necessary to preheat uniformly to avoid stresses inside the copper casting due to rapid local cooling after the copper liquid enters the mold.

Control pouring speed: the pouring speed needs to be appropriate, too fast may cause gas inclusions, eddy currents and defects through the casting; too slow may lead to premature cooling of the copper liquid, unable to completely fill the mold, resulting in cold segregation and shrinkage holes.

Gate design: Reasonable design of the location and shape of the gate to ensure that the copper liquid can enter the mold smoothly and evenly.

Exhaust design: Exhaust channels should be designed in the mold to discharge air and gas in time to prevent the production of porosity, inclusions and other defects.

Control of cooling rate: For thick-walled copper castings, the difference between the internal and external cooling rates can be reduced by controlling the cooling rate to avoid deformation or internal stresses in the copper castings.

Heat treatment: If necessary, heat treatment (such as annealing or aging treatment) is carried out after cooling to release the internal stresses of copper castings and improve the organizational properties.

Casting cleaning: After pouring, remove excess sprues, risers and sand cores. Check the surface of copper castings for oxidized skin, porosity, cracks and other defects.

Safety Precautions

Protective measures: High temperature and dangerous operation during casting process, appropriate personal protective equipment should be worn, such as heat-insulating gloves, masks, protective clothing, etc., to avoid scalding caused by splashing of high temperature liquid.

Operating environment: Keep the working area well ventilated, especially during melting and casting operations, to avoid the accumulation of harmful gases.

Summarize

The casting process of copper castings requires strict control of melting temperature, degassing treatment, pouring speed and mold preheating and other key parameters. Reasonable design of the pouring system and control of the cooling process can ensure the high quality of castings and production stability.