Magnesium CNC Machining Services: Everything You Need to Know

Magnesium Alloy AZ31B

• Description: AZ31B is a general-purpose magnesium alloy with excellent strength and moderate ductility, making it ideal for machining and forming.
• Characteristics: High machinability, lightweight, good corrosion resistance, and weldability. It can be processed using conventional CNC techniques.
• Applications: Commonly used in aerospace, automotive, and electronics industries for parts requiring lightweight and moderate strength, such as housings, brackets, and panels.

Magnesium Alloy AZ91D

• Description: AZ91D is the most commonly used magnesium alloy due to its balance of strength and ductility, along with high corrosion resistance.
• Characteristics: Superior corrosion resistance, high strength-to-weight ratio, and excellent casting ability. It is suitable for applications requiring high corrosion resistance and strength.
• Applications: Often used in the automotive and electronics sectors for parts like gear housings, steering wheels, and electronic enclosures.

Magnesium Alloy WE43

• Description:WE43 is a high-performance magnesium alloy, known for its excellent strength and resistance to high temperatures.
• Characteristics: High strength, excellent creep resistance at elevated temperatures, and superior corrosion resistance. It is suitable for components subjected to harsh environments and high temperatures.
• Applications: Common in aerospace, motorsport, and defense industries for structural components, engine parts, and gearbox casings.

Magnesium Alloy AM60B

• Description: AM60B is a ductile magnesium alloy, often preferred for its toughness and good impact resistance.
• Characteristics: Good ductility and impact resistance, high energy absorption in collisions, and moderate corrosion resistance. It is well-suited for components where safety is crucial.
• Applications: Extensively used in the automotive industry for structural parts like seat frames, dashboards, and steering wheel components, where energy absorption is important.

Magnesium Alloy ZK60A

• Description: ZK60A is a high-strength magnesium alloy, typically used for applications requiring strong, lightweight components.
• Characteristics: High yield strength, moderate corrosion resistance, and good machinability. It is ideal for high-stress environments but requires surface treatments to improve corrosion resistance.
• Applications: Used in aerospace, automotive, and sports equipment for parts like helicopter components, wheels, and structural components.

Magnesium Alloy QE22

• Description: QE22 is a magnesium alloy specifically engineered for high-performance applications, known for its good mechanical properties.
• Characteristics: Excellent strength at elevated temperatures, good creep resistance, and high fatigue strength. Suitable for parts that undergo continuous stress.
• Applications: Primarily used in the aerospace and defense industries for components that need to maintain strength at high temperatures, such as engine blocks and turbine components.

Advantages and disadvantages of Magnesium CNC Machining

Advantages of Magnesium CNC Machining

1. LightweightMagnesium alloys are among the lightest structural metals, offering an excellent strength-to-weight ratio. This makes them ideal for aerospace and automotive applications, where reducing component weight boosts performance and fuel efficiency.
2. High MachinabilityMagnesium is highly machinable, allowing faster cutting speeds and reduced tool wear. This makes CNC machining of magnesium efficient, lowering both production time and operational costs.
3. Complex GeometriesMagnesium alloys can be precisely machined into intricate shapes, making them well-suited for parts with complex geometries. This precision allows for detailed designs in components that require high accuracy.
4. Good Damping PropertiesMagnesium’s natural vibration-damping ability makes it valuable in applications requiring noise reduction and enhanced stability, such as automotive frames and electronics, contributing to greater comfort and durability.
5. RecyclabilityMagnesium alloys are highly recyclable, promoting material sustainability. This recyclability aligns well with environmentally conscious manufacturing, reducing material waste and energy consumption.

Disadvantages of Magnesium CNC Machining

1. FlammabilityMagnesium is highly flammable, especially in chip or powder form, posing significant fire risks during machining. This requires specialized handling and cooling systems to ensure safety.
2. Heat GenerationMachining magnesium generates substantial heat, increasing the risk of ignition and potential warping. Effective cooling strategies are essential to manage this heat and maintain material integrity.
3. Tool WearAlthough relatively soft, magnesium’s abrasiveness can lead to tool wear over time, especially when working with certain alloys. Frequent tool maintenance or replacement may be necessary.
4. Surface DeformationMagnesium’s low melting point makes it prone to surface deformation under high machining speeds. This can result in compromised precision and the need for post-machining surface treatments.

Surface Finishes For CNC Machined Magnesium Parts

As Machined

This finish leaves the part with the natural surface created by CNC machining, often suitable for functional parts that do not require additional aesthetic or protective treatments.

Polishing

Polishing creates a smooth, reflective surface on magnesium parts, enhancing appearance while slightly reducing surface roughness. It’s ideal for applications where aesthetics are important.

Sand Blasting

Sand blasting uses abrasive particles to clean and texture the surface, removing imperfections and creating a matte finish that improves paint or coating adhesion on magnesium parts.

Tumbling

Tumbling involves placing parts in a rotating barrel with abrasive media, resulting in a smoother surface and rounded edges. It’s commonly used to prepare magnesium parts for further finishing.

Alodine

Alodine, or chromate conversion coating, provides a thin, protective layer on magnesium to improve corrosion resistance. It’s widely used in aerospace applications for added durability.

Heat Treatment

Heat treatment can enhance the mechanical properties of magnesium, improving strength and stability. This process is applied prior to other surface treatments to ensure part performance.

Electrophoresis

Electrophoresis applies an even, thin protective coating to magnesium parts, enhancing corrosion resistance and providing a consistent finish, often used for parts requiring precise coating thickness.

Anodizing

Anodizing creates a protective oxide layer on magnesium, improving corrosion resistance and allowing for coloring options. However, magnesium requires specific anodizing processes different from those for aluminum.

Safety Tips for CNC Machining Magnesium

Control Dust and Chips

Magnesium dust and chips are highly flammable. Use effective extraction systems to prevent buildup, and regularly clean workspaces to reduce the risk of ignition.

Implement Proper Cooling

Due to magnesium’s low ignition temperature, apply coolant carefully to manage heat. Avoid water-based coolants, as they may react with magnesium, and instead use a mineral oil-based coolant for safer heat management.

Use Non-Sparking Tools

Non-sparking tools reduce the chances of accidental ignition. This includes using tools designed specifically for magnesium and maintaining sharp, clean cutting tools to minimize friction.

Store Magnesium Properly

Store magnesium dust, chips, and scrap in containers with secure lids, preferably in a dry, non-combustible area. Dispose of them safely according to local regulations to prevent fire hazards.

Prepare for Fire Safety

Equip the workspace with Class D fire extinguishers, as magnesium fires cannot be extinguished with water or CO₂ extinguishers. Train all personnel in magnesium-specific fire response procedures for quick, safe reactions.