Casting

 

 

 

√ Sand Casting, it's a traditional method of using sand molds, and molten copper or copper alloy is poured into the mold. The cast is done after solidification, and then the sand mold is removed. Advantages are low tooling cost, suitable for large and complex castings, wide range of alloys are also suitable. The disadvantages are relatively low dimensional accuracy, rough surface finish as well as limited to design options.

 

 

 

√ Investment Casting, also called dewaxing casting, it uses a wax pattern coated with a refractory material to create a mold. Molten copper is then poured into the mold, and after solidification, the wax is melted away and the wax mold is broken to reveal the casting. The advantages are high dimensional accuracy, excellent surface finish, and this solution is suitable for complex shapes and intricate details. The disadvantages are high tooling cost, limited to smaller castings. Plus, production leadtime is longer than sand casting.

 

 

√ Die Casting, it is a high-pressure casting process using reusable metal dies to create the mold. Molten copper is injected into the die under high pressure, and after solidification, the die is opened to reveal the casting. The advantages are high production rate, excellent dimensional accuracy, good surface finish, suitable for mass production. The disadvantages are high tooling cost, limited to simpler shapes, and it is restricted to specific copper alloys.

 

 

√ Centrifugal Casting, this process utilizes centrifugal force to distribute molten copper within a mold with rotating at high speed, and this solution will cause the molten copper to solidify against the mold walls. The benefits are excellent density and uniformity, suitable for cylindrical and tubular shapes, improved mechanical properties. The short comings are limited to specific shapes, higher equipment cost, potential internal defects like pores.

 

 

 

 Horizontal Continuous Casting

√ Horizontal Continuous Casting,this process is designed to continuously pour molten copper into a water-cooled mold for effectively solidifying. It is then drawn out as a continuous strand or copper tube. The advantages are high production rate, low labor cost, suitable for producing long and uniform shapes. The limits are suitable for some specific shapes, and it requires specialized equipment. Plus, its surface imperfections are very obvious, and it often requires milling surface which is often a layer of copper oxide. Horizontal continuous casting is widely used in the production of copper ingots for various applications, including:

1. Electrical conductors

2. Building and construction

3. Industrial machinery

4. Electronics

√ Other Casting Solutions, such as shell mold casting, plaster mold casting, and lost foam casting.

How to choosing the right casting process for your products?

The selection of copper casting solutions are really depending on various factors, and it includes following aspects:

√ Complexity of the part, intricate shapes may require investment casting or die casting for high accuracy.

√ High-volume production may favor die casting or continuous casting for efficiency.

√ Specific alloys may have limitations for certain casting processes. For example, copper alloy with high percentages of elements, such as zinc, nickel, or tin, can be more challenging to cast by horizontal continuous casting because these elements can affect the solidification behavior of the molten copper, which will lead to potential issues like segregation, cracking, or porosity. Therefore alternative casting processes like vertical continuous casting or static casting might be more suitable. Reactive alloys contain elements which react readily with air or moisture, such as aluminum or magnesium, can be challenging to cast using horizontal continuous casting because these elements can form oxide layers or other surface defects during the casting process, impacting the quality of the ingot. Therefore, special precautions, such as using protective atmospheres or casting in a vacuum environment, might be necessary for the alloys associated with aluminum and magnesium.

√ Tooling and labor cost.

√ Equipment costs

What are the common casting quality issues for copper and copper alloy products?

√ Porosity, it refers to the presence of gas bubbles or voids within the cast copper products, and this can be caused by factors such as entrapped air, dissolved gases, or improper mold design. Porosity can weaken the casting and make it more susceptible to cracking or corrosion, and severity level of porosity needs to be classified before the casting production starts.

√ Shrinkage Cavity, it is actually depression or void that form in the casting due to the contraction of the copper during solidification. This could be caused by fast cooling or when the mold design does not allow for sufficient feeding of molten copper to compensate for shrinkage.

√ Crack, it can occur in the casting due to various factors, including stresses induced by rapid cooling, shrinkage, or improper mold design. Cracks certainly weaken the casting and make it more susceptible to failure under load.

√ Segregation, it actually refers to the uneven distribution of alloying elements within the casting. This can occur due to differences in the solidification rates of different phases or components of the alloy, and it can cause variations in the mechanical properties and corrosion resistance of the casting.

√ Inclusions, it is usually caused by trapping foreign particles in the cast copper, and it may include oxides, slag, or other contaminants that can weaken the casting and reduce its machinability.

√ Other Surface Defects, it include wide range of defects such as cold shuts, laps, or scabs, which might be caused by improper mold filling or pouring practices, or mold contamination.

√ Microstructural Defects, these defects such as grain size variations or intermetallic phases, can affect the mechanical properties and corrosion resistance of the casting, and microstructural defects can be caused by improper melting or casting practices.

Applications of Copper Alloy Casting Parts

Copper alloy casting parts have following benefits:

√ High strength and wear resistance

√ Good electrical conductivity

√ Excellent thermal conductivity

√ Strong corrosion resistance

√ Non-magnetic properties

Due to the above-mentioned features, and the copper casting products are widely used in following industries:

1. Industrial machinery such as bearings, gears, valves and fittings.

2. Electrical components such as electrical contacts, busbars, heat sinks.

3. Marine applications like propeller

4. Plumbing like pipes and fittings

5. Medical devices, surgical instruments and implants

6. Decorative applications such as sculptures, jewelry, and architectural hardware

Fabmann offers a wide range of copper & copper alloy casting service, and our production team and engineering team are very experienced in production controls which include:

√ Chemical Composition Analysis

√ Visual Inspection

√ Dimensional Inspection

√ Mechanical Testing

√ Microstructural Analysis

√ Non-Destructive Testing (NDT)

Fabmann has a comprehensive quality management system (QMS), and we are able deliver consistent quality throughout the casting process. Our team implements documentation procedures, quality control checks, and corrective action plans to address any identified issues. Therefore, our team focus on implementing quality control measures throughout the casting process, and we also implement continuous improvement to enhance the overall quality of the casting process from tooling designing to finished products.