Aluminum CNC Machining

Billet aluminum is formed by forging or extrusion.

Most common billet aluminum material used in China are 6061 T6, 7075 T6, and 2024 T4. Other CNC aluminum alloys are below.

Die-cast aluminum alloys can form the basic shape of components. For areas requiring assembly, excess aluminum is removed via CNC machining (milling/turning), enabling efficient and cost-effective mass production of lightweight mechanical parts. The commonly used materials for die-cast aluminum CNC machining are as follows.

Common Die-Casting Aluminum Alloys for CNC Machining(Domestic & International)

Domestic Grades (GB/T 15115-2009, China)

• YL102 (Al-Si12): Excellent fluidity, suitable for die-casting complex components; applied in instrument housings, electrical enclosures.Equivalent grades: ADC1, A413.0, AlSi12
• YL104 (Al-Si10Mg): Medium strength, good hot crack resistance and weldability; applied in hydraulic parts, motor end covers.Equivalent grades: ADC3, A360, AlSi10Mg0.3
• YL112 (Al-Si9Cu4): High strength, superior machinability; applied in automobile cylinder blocks, gearbox housings.Equivalent grades: ADC10, A380, AlSi9Cu3
• YL113 (Al-Si11Cu3): High fluidity, good corrosion resistance; applied in thin-walled complex components, electronic enclosures.Equivalent grades: ADC12, 383.0, AlSi11Cu3
• YL117 (Al-Si17Cu5Mg): High silicon content for wear resistance, excellent thermal conductivity; applied in engine cylinder liners, pistons.Equivalent grades: ADC14, B390, AlSi17Cu5Mg

International Mainstream Grades

1. ASTM (USA)
   • A380: Universal grade with balanced comprehensive properties; for automotive/industrial components
   • A356 (Al-Si7Mg): Heat-treatable for reinforcement; for wheel hubs, structural components
   • A413.0: High silicon content, excellent fluidity; for thin-walled components
2. JIS (Japan)
   • ADC12 (Al-Si11Cu3): High fluidity, ideal for complex die-castings
   • ADC10 (Al-Si9Cu4): Better toughness, for large die-cast components
   • ADC3 (Al-Si10Mg): Good hot crack resistance, for hydraulic parts
3. • AlSi12: High silicon content, superior fluidity
   • AlSi9Cu3: Universal grade, equivalent to A380
   • AlSi7Mg0.3: Equivalent to A356, high strength and toughnessEN (Europe)

Core Grade Cross-Reference Table

Key Material Selection Guidelines for Die Casting Aluminum CNC Machining Components.

• Al-Si/Cu series (YL112/YL113, A380, ADC12) are the first choice for most general die-casting components.
• For high strength and toughness requirements, select Al-Si/Mg series (YL104, A356) featuring heat-treatable reinforcement.
• For wear resistance/thermal conductivity needs, opt for high-silicon series (YL117, B390, ADC14).

Aluminum Alloy Grades for Sand Casting, Gravity Die Casting & Low Pressure Die Casting + Process Differences & Universal Grades

I. Alloy Grades for Each Process (GB/T 1173 China Domestic + International Equivalents, divided into Universal & High-requirement Grades)

1. Sand Casting

2. Gravity Die Casting

3. Low Pressure Die Casting (LPDC)

II. Core Differences of the Three Casting Processes (Key Basis for Grade Selection)

III. Universal Core Grades for the Three Processes (cross-process compatible, mature supply chain & cost-effective)

China Domestic Grades

International Equivalents

Core Characteristics of Universal Grades

1. Heat-treatable for strength and toughness enhancement, adaptable to different stress requirements via subsequent processes;
2. Moderate fluidity, compatible with the slow cooling of sand molds and fast cooling of metal molds;
3. Low impurity content, less prone to cracking and shrinkage porosity, high forming qualification rate across processes;
4. Excellent machinability, suitable for CNC turning/milling, meeting assembly precision requirements.

Application Scenarios of Universal Grades

1. Heat treatment requirements: Forged aluminum profiles are pre-heat-treated, usually to T4/T6 temper; cast aluminum products can be post-heat-treated, generally also to T6 temper. Die-cast aluminum products are typically not suitable for heat treatment.
2. Product structure: Complex structures require blanks to be produced via sand casting, gravity die casting or low pressure die casting, followed by machining to meet assembly precision requirements.
3. Product dimensions: Some oversized products can only be manufactured by aluminum sand casting, as other casting methods are limited by the size of casting equipment.
4. Production efficiency: Die casting combined with machining offers the highest efficiency, while sand casting paired with machining has the lowest efficiency.
5. Surface roughness & precision: Sand casting yields the roughest surface and lowest precision, followed by gravity die casting, then low pressure die casting; pure machining achieves the highest surface precision.
6. Unit cost: For sufficiently large order quantities, the unit cost of die casting plus machining is the lowest after the mold cost is evenly amortized.
7. Internal material density: Aluminum profiles are formed by forging or extrusion, resulting in an extremely dense internal structure. In contrast, blanks from casting and die casting often have internal defects such as porosity or shrinkage porosity.