Improving the surface quality and accuracy of copper castings is a systematic project, involving all aspects from raw material selection to post-treatment. The following are specific measures:

Raw material control

Selection of high-quality copper alloy materials: according to the specific requirements of use, choose copper alloy raw materials with high purity and less impurities. For example, for copper castings requiring higher electrical conductivity and corrosion resistance, copper can be selected; For occasions requiring higher strength and wear resistance, brass or bronze can be used. Ensure that the chemical composition of the raw material meets the standard requirements to avoid affecting the quality of the casting due to excessive impurity content.

Strict inspection of raw materials: Strict inspection of purchased copper alloy materials, including chemical composition analysis, physical properties testing, etc. Advanced testing methods such as spectral analysis are adopted to ensure the stable and reliable quality of raw materials and prevent unqualified materials from entering the production process.

Mold design and manufacturing

Optimize the mold structure: design a reasonable mold structure to ensure that the copper liquid flows smoothly during the filling process, avoid turbulence, eddy current and other phenomena, in order to reduce the surface defects of the casting. For example, the use of appropriate gate location and number, so that the copper liquid can evenly fill the mold cavity.

Improve the mold manufacturing accuracy: the use of advanced processing equipment and technology to improve the mold manufacturing accuracy and surface quality. The dimensional accuracy and surface roughness of the die directly affect the accuracy and surface quality of the copper casting, so it is necessary to ensure that the machining accuracy of the die is within the tolerance range and the surface roughness meets the requirements.

Choose the right mold material: according to the production batch and process requirements of copper casting, choose the right mold material. For large batch production, the mold steel with good thermal stability and high strength can be selected to ensure the dimensional stability of the mold during repeated heating and cooling, and reduce the influence of mold deformation on the accuracy of the casting.

Casting process optimization

Precise control of melting parameters: strictly control the melting temperature, time and furnace atmosphere of copper alloy. Appropriate melting temperature can ensure the fluidity and purity of copper liquid, too high temperature will lead to copper liquid suction, oxidation serious, affecting the surface quality of castings; If the temperature is too low, the fluidity of copper liquid will be poor, and it is easy to produce defects such as insufficient pouring and cold insulation.

Adopt advanced casting method: According to the structural characteristics and precision requirements of copper casting, choose the appropriate advanced casting method, such as precision casting, pressure casting, centrifugal casting, etc. Precision casting can obtain castings with high dimensional accuracy and good surface quality; Pressure casting can improve the filling capacity of copper liquid, reduce the internal defects of castings and improve the surface quality.

Improve filling and solidification conditions: In the casting process, a reasonable filling speed and solidification sequence are used to ensure that the copper liquid can fill the mold cavity smoothly and solidify in the expected order. For example, by setting a reasonable riser and cold iron, adjust the solidification direction of the casting, achieve sequential solidification, reduce shrinkage holes, shrinkage and other defects, improve the density and surface quality of the casting.

Quality control in production process

Keep the production environment clean: The environment of the casting workshop has an important impact on the surface quality of copper castings. Keep the workshop clean, reduce the mixing of dust, sand and other impurities, and prevent these impurities from adhering to the surface of the casting or entering the copper liquid, forming defects such as inclusions.

Strengthen the process inspection: In the production process of copper casting, strengthen the inspection of each process, timely detection and treatment of problems. For example, check the dimensional accuracy, surface quality and compactness of the sand mold and sand core during the molding and core making process; In the closing process, check the assembly accuracy and sealing of the sand box to prevent problems such as wrong box and fire running.

Post-treatment technology

Machining: According to the accuracy requirements of the casting, appropriate machining, such as turning, milling, grinding, etc., to improve the dimensional accuracy and surface roughness of the casting. Through precise processing technology and equipment, the residual and defects on the surface of the casting are removed, so that the casting can reach the size and surface quality required by the design.

Surface treatment: The use of appropriate surface treatment processes, such as polishing, electroplating, electroless plating, oxidation treatment, etc., to further improve the surface quality of copper castings. Polishing can make the surface of the casting more smooth, improve the gloss; Electroplating and electroless plating can form a uniform, dense metal or alloy coating on the surface of the casting, improving corrosion resistance and decoration