Magnesium cnc machining
We have our own 3-axis, 4-axis, and 5-axis CNC machining centers, and our employees have an average of over 10 years of CNC machining experience. Contact us for pricing and more information on magnesium CNC machining.
What is magnesium cnc machining ?
CNC machining of magnesium alloys uses computer-programmed CNC machine tools to perform cutting and other operations on magnesium alloys, which are 30% lighter than aluminum, to precisely manufacture parts. It is highly efficient, suitable for mass production, and achieves an accuracy of 0.005 mm. It can process complex structures with good surface quality and is commonly used in the 3C, automotive, and aerospace industries.
Common magnesium type for cnc machining
AZ91D Magnesium Alloy
Characteristics: High aluminum content (approximately 9%), outstanding strength and hardness, relatively low cost, making it one of the most widely used magnesium alloys. Its Knoop hardness (HK) reaches 76.2, and its corrosion resistance is superior to some aluminum alloys.
AZ31 Magnesium Alloy
Characteristics: Lower aluminum content (approximately 3%), good plasticity, but slightly lower strength and hardness than AZ91D (Knoop hardness HK is 51.1).
ZK60 Magnesium Alloy
Characteristics: High-strength magnesium alloy, suitable for load-bearing structures, good wear resistance, but relatively brittle, making it difficult to process.
Mg-Mn Alloys: Excellent corrosion resistance, suitable for parts in chemical equipment and humid environments.
Mg-RE Alloys: Contain rare earth elements, stable high-temperature performance, used in high-temperature engine components.
Mg-Li Alloys: Extremely low density, the lightest known metallic structural material, suitable for applications where weight is extremely sensitive (such as satellite components).
Surface finish for cnc machining magnesium part
Based on over 15 years of CNC machining experience, we have compiled the following list of surface finish processes used for various precision-machined parts made from magnesium material.
Machined finish
The prototype processed by the machine tool retains traces of tool machining.
Anodizing
Anodizing enhances the corrosion and wear resistance of metals and enables coloring and coating, suitable for metals such as aluminum, magnesium, and titanium.
Polish
Polishing enhances surface finish and aesthetic appeal, suitable for materials such as metals, ceramics, plastics, and PMMA.
Sand blasting
Sandblasting involves propelling abrasive material at high pressure or mechanically onto a workpiece to achieve a clean, roughened, and matte finish.
Brushed finish
Brushed finish creates a textured pattern on metal surfaces, enhancing aesthetic appeal. Suitable for aluminum, copper, stainless steel, and other materials.
Powder coating
Powder coating is applied to the workpiece surface via electrostatic adhesion, then cured at high temperatures to form a dense coating, enhancing the corrosion resistance of metal and plastic surfaces.
Electroplating finish
Metal plating is deposited onto material surfaces through electrolytic processes to enhance corrosion resistance and wear resistance. This technique is suitable for metals and certain plastics.
Black oxidize
A black oxide coating is formed on metal surfaces through chemical oxidation, offering low cost, a simple process, and reduced light reflection.
Electropolish
Removes microscopic protrusions from metal surfaces through electrochemical anodic dissolution, creating a smooth, dense surface free of residual stress and highly corrosion-resistant. Capable of processing complex metals and conductive materials.
Alodine
Forms a protective coating on surfaces through chemical conversion, enhancing corrosion resistance and adhesion. Environmentally friendly with excellent conductivity, suitable for aluminum and magnesium alloys.
Heat treatment
By altering the internal microstructure of metallic materials through heating, this process enhances hardness, strength, toughness, and wear resistance. It is suitable for metals such as steel, aluminum alloys, copper alloys, and titanium alloys.
Advantage of cnc machining magnesium
Significant Lightweight Advantages
Magnesium alloy has a density of only 1.74 g/cm³ (2/3 that of aluminum, 1/4 that of steel), making it the lightest metal structural material for engineering applications.
Benefits: Parts manufactured using CNC machining can significantly reduce product weight, improving energy efficiency (e.g., electric vehicle range) or portability (e.g., electronic products).
High Machining Precision and Efficiency
CNC Technology Characteristics: Computer programming control achieves micron-level precision (±0.01 mm), enabling the machining of complex curved surfaces, irregularly shaped holes, and other structures that are difficult to achieve with traditional processes.
Efficiency Improvement: Automated machining reduces manual intervention, making it suitable for mass production (e.g., daily production capacity of thousands of mobile phone mid-frames).
Excellent Surface Quality
Magnesium alloy has a low surface roughness after machining (Ra≤0.8μm), allowing it to be directly used for assembly, reducing post-processing steps such as polishing and sandblasting, and lowering overall costs.
Excellent Heat Dissipation Performance: Magnesium alloys have a thermal conductivity of 156 W/(m·K) (1.5 times that of aluminum). The precision CNC-machined structure optimizes heat dissipation paths, making it suitable for high-power-density applications (such as 5G base stations and gaming laptops).
Electromagnetic Shielding Performance: Magnesium alloys offer excellent shielding against electromagnetic waves. The CNC-machined sealing structure further enhances shielding efficiency, meeting the anti-interference requirements of electronic devices.
High Recyclability: Magnesium alloys have a recycling rate exceeding 95%, and CNC-machined scraps can be 100% recycled and reused, aligning with green manufacturing trends.
Application of cnc machining magnesium
3C Electronics
Applications: Laptop casings, mobile phone frames, tablet stands.
Advantages: Lightweight design improves portability, improved heat dissipation extends device lifespan, and electromagnetic shielding reduces signal interference.
Automotive Industry
Applications: Steering wheel frames, dashboard supports, seat adjustment mechanisms.
Advantages: 10%-15% weight reduction can reduce fuel consumption by 5%-8%; CNC-machined precision structures meet safety standards (such as crash tests).
Aerospace
Applications: Drone arms, satellite structural components, aircraft doors.
Advantages: Every 1kg reduction saves commercial flights over $3,000 in fuel costs annually; CNC-machined lightweight, high-strength structures are key.
Medical Devices
Applications: Portable ultrasound machine casings, surgical robot joints.
Advantages: Excellent biocompatibility; CNC-machined burr-free surfaces reduce infection risk while meeting precision transmission requirements.
Sports Equipment
Applications: Bicycle frames, golf club heads, carabiners.
Advantages: Lightweight design improves motion performance, and the streamlined design spun by CNC machining optimizes aerodynamics.
FAQ of cnc machining magnesium
How to select appropriate cutting tools and cutting parameters in CNC machining of magnesium alloys?
Tool Material: Fine-grained/ultra-fine-grained cemented carbide (K-type/ISO N-type), or diamond-coated tools (suitable for mass production) are recommended.
Tool Geometry: A large rake angle (>10°) reduces cutting forces and provides a sharp cutting edge; a large clearance angle (>10°) reduces friction.
Cutting Parameter Optimization: High Spindle Speed: Magnesium has good thermal conductivity and can withstand spindle speeds >300 m/min (typically higher than aluminum alloys).
Large Feed Rate: Utilize the low cutting force characteristics; feed per tooth (fz) >0.1 mm/tooth.
Large Depth of Cut/Width of Cut: Within the limits of machine tool rigidity, use the largest possible depth of cut (ap) and width of cut (ae) to reduce the number of passes.
Principle: Maintain a high metal removal rate (MRR) while avoiding excessive heat accumulation in the cutting zone.
Path planning: Ensure continuous cutting with the tool, avoiding interruptions that generate high temperatures; optimize the path to reduce idle travel; roughing focuses on efficiency, while finishing focuses on precision.
What are the main advantages of CNC machining of magnesium alloys?
Lightweight: Density is only 1.74 g/cm³ (2/3 of aluminum, 1/4 of steel), significantly reducing product weight (e.g., 15%-20% weight reduction for automotive parts).
High precision and efficiency: CNC technology achieves ±0.01 mm level precision, machining complex structures (e.g., irregular holes in 3C products, thin-walled aerospace parts).
Heat dissipation and electromagnetic shielding: Thermal conductivity of 156 W/(m·K), superior to aluminum and steel; naturally shields against electromagnetic interference, suitable for high-power devices (e.g., 5G base stations, gaming laptops).
Recyclability: Scrap material recycling rate exceeds 95%, aligning with green manufacturing trends.
Shock absorption performance: Resilient shock absorption properties absorb vibration and noise, improving the comfort of components such as car seats and transmission systems.
What are some common surface treatment methods after CNC machining of magnesium alloys?
Chemical oxidation: Low cost and simple operation, but the film is thin (1-5μm) with limited corrosion resistance, suitable for temporary protection or as a base coat.
Anodizing: Generates a hard ceramic film with better corrosion and wear resistance than chemical oxidation, but requires sealing treatment (e.g., high-temperature curing epoxy resin).
Micro-arc oxidation (MAO): Generates a 10-30μm thick ceramic film, significantly improving corrosion and wear resistance, suitable for outdoor/highly corrosive environments (e.g., automotive wheels).
Electroplating: Commonly used plating materials are nickel, copper, or chromium, requiring pretreatment (e.g., zinc immersion) to improve adhesion, suitable for decorative or functional needs (e.g., conductivity).
Self-healing composite oxidation technology: Generates a dense 10-120μm ceramic film with active/passive repair capabilities, achieving 500-1000 hours of salt spray resistance, suitable for high-end fields (e.g., aerospace, new energy vehicles).
Does CNC machining of magnesium alloys pose safety risks? How can these be mitigated?
Risks: High-temperature sparks are easily generated during magnesium alloy cutting, and the dust may spontaneously combust (ignition point approximately 500℃).
Precautions: Wet cutting: Use emulsion or oil mist cooling to reduce the temperature of the cutting zone.
Equipment protection: Equip the machine tool with an automatic fire extinguishing system (such as a CO₂ fire extinguishing device) and a dust collection device.
Good sealing is essential to prevent dust/oil mist leakage.
Operating procedures: Do not use compressed air to blow away dust (may cause static sparks).
Keep the cutting area clean and remove accumulated chips daily.
Material selection: Prioritize flame-retardant magnesium alloys (such as AZ series variants containing calcium and strontium).
In which industries is magnesium alloy CNC machining typically used?
3C electronics: Laptop casings, mobile phone frames (weight reduction + heat dissipation + electromagnetic shielding).
Automotive Industry: Engine blocks, transmission housings (30%-40% weight reduction), wheels, hubs (reduced unsustainable mass), seat frames, steering wheels (improved safety and comfort).
Aerospace: Aircraft fuselage frames, wing spars (15%-20% weight reduction), engine mounts, control hinges (high temperature/high vibration resistance).
Medical Devices: Portable X-ray machines, ultrasound diagnostic instrument housings (lightweight + biocompatibility), bone screws, bone plates (biodegradable).
Robotics and Automation: Robot joints, arms (lightweight + high strength), automated equipment housings (corrosion resistant + protection of precision components).
