Summary:
- Due to the relatively low strength and hardness, small plasticity, low tool wear and high thermal conductivity of aluminum alloy, the cutting temperature is lower, making it easier to cut and a suitable material for high-speed cutting. However, the low melting point of aluminum alloy leads to increased plasticity at high temperatures and pressures, resulting in substantial friction at the cutting interface, which can cause tool sticking. In particular, annealed aluminum alloys are difficult to obtain low surface roughness.
- Compared to steel and brass, aluminum alloy has two distinct characteristics: the material is soft and less rigid and its modulus of elasticity is low. These two factors significantly affect the machinability of aluminum alloy. Therefore, when machining aluminum alloy parts, it is necessary to properly clamp and support the part and keep cutting tools sharp. Otherwise, the part tends to move away from the cutting tool. Sometimes irregular grooves and shiny compression marks appear on the surface of the workpiece. One possibility is that the pressure of the cutting tool on the workpiece is not normal, and another possibility is that the cutting tool rubs on the surface of the workpiece when there is insufficient clamping or vibration occurs, resulting in compression and cutting powder. Then, when the gap or elasticity disappears, the cutting tool penetrates the surface of the workpiece and leaves grooves.
- To achieve a smooth surface finish on workpieces, it is best to use a combination of rough and finish cutting. This is because various qualified blanks tend to have some oxide layers that cause considerable wear on cutting tools. If sharp and polished cutting tools are used for the final cutting process, the above requirements can be met.
- The cutting properties of aluminum alloy are generally divided into two categories: category 1 refers to industrial pure aluminum and annealed aluminum alloys with hardness less than 80HB, while category 2 refers to the deformation of aluminum alloys in the seasoned and aged states. The parameters of the aluminum alloy cutting process depend on these categories.
Typical cutting parameters for high-speed steel and carbide cutting tools
| Operation | Tool materials | Machining Category | Cutting speed (m/min) |
Back tilt angle (°) |
Final Relief Angle (°) |
Feed rate (mm/r) |
Cutting depth (mm) |
Refrigerator |
| Difficult turning. | High speed steel. | 1 | 200-400 | 40433 | 30-40 | ≤1 | 40252 | no |
| two | 100-250 | 40400 | 20-30 | 0.2-0.5 | 40252 | no | ||
| Hard metal | 1 | 600-1200 | 40369 | 20-30 | 0.3-0.6 | 40252 | no | |
| two | 200-400 | 40369 | 40471 | 0.25-0.6 | 40252 | no | ||
| Finish spinning. | High speed steel. | 1 | 400-900 | 40400 | 40-50 | 0.05-0.3 | 0.3-2.5 | Cutting Fluid (Emulsion or Cutting Oil) |
| two | 200-500 | 40368 | 30-40 | 0.03-0.25 | 0.3-2.5 | |||
| Hard metal | 1 | ≤2400 | 40400 | 20-30 | ≤0.15 | 0.3-2.5 | Cutting Fluid (Emulsion or Cutting Oil) | |
| two | 250-700 | 40368 | 40471 | 0.05-0.1 | 0.3-2.5 |
Typical cutting parameters for diamond tools
| Machining Category | Milling speed (m/min) |
Feed Rate (mm/r) |
Cutting depth for long chip alloy (mm) |
Cutting depth for short chip alloy (mm) |
| 1 | ≤3000 | 0.02-0.1 | 0.02-0.3 | 0.02-0.6 |
| two | 800-1400 | 0.02-0.1 | 0.02-0.3 | 0.02-0.6 |
Typical milling parameters for aluminum alloy
| Operation. | Tool material. | Machining Category | Milling speed (m/min) |
Bond angle (°) |
Side tilt angle (°) |
Feed rate (mm/r) |
Milling depth (mm) |
Helix angle (°) |
Refrigerator |
| Rough milling | High speed steel | 1 | 300-600 | 8 | 25 | 0.1-0.5 | 40229 | 30-40 | no |
| two | 150-400 | 6 | 20 | 0.1-0.5 | 40229 | ≤30 | Water-soluble coolant. | ||
| Hard metal | 1 | ≤2500 | 8 | 20 | 0.1-0.6 | 40229 | 30-40 | no | |
| two | 300-800 | 6 | 15 | 0.1-0.6 | 40229 | ≤30 | no | ||
| Finish milling | High speed steel | 1 | ≤1500 | 12 | 30 | 0.03-0.1 | ≤0.5 | 30-40 | Water-soluble coolant. |
| two | 250-800 | 10 | 25 | 0.03-0.1 | ≤0.5 | ≤30 | Coolant or water-soluble oil. | ||
| Hard metal | 1 | ≤3000 | 12 | 25 | 0.03-0.1 | ≤0.5 | 30-40 | Water-soluble coolant. | |
| two | 500-1500 | 10 | 20 | 0.03-0.1 | ≤0.5 | ≤30 | Coolant or water-soluble oil. |
Typical parameters for helical drilling in aluminum alloy
| Tool material | Type of cut | Milling speed (m/min) | Point angle (°) | Helix angle (°) | Feed rate (mm/r) | Secondary relief angle (°) | Refrigerator |
| High speed steel | 1 | 100-120 | 140 | 45-30 | 0.02-0.5 | 17-15 | Water Soluble Coolant |
| two | 80-100 | 120 | 35-20 | 0.02-0.5 | 15 | Water Soluble Coolant | |
| Hard metal | 1 | 200-300 | 130 | 25-15 | 0.06-0.3 | 12 | No refrigerant or water-soluble refrigerant |
| two | 100-200 | 120 | 40466 | 0.06-0.3 | 12 | No refrigerant or water-soluble refrigerant | |
| Observation | Low speed is recommended for drilling small holes. | When drilling thin plates, it is recommended to increase the tip angle or use a drill with a positive rake angle. | When drilling small holes, it is recommended to use a drill with a small helix angle. | The feed rate for drilling small holes should be small. | When grinding the secondary relief angle, it is important to select the appropriate angle. | It is best to use a water-soluble coolant | |
Typical drilling parameters before tapping in aluminum alloy
| Standard thread | M3 | M3.5 | M4 | M4.5 | M5 | M6 | M8 | M10 | M12 | M14 | M16 |
| Hole diameter (mm) | 2.7 | 3.75 | 3.6 | 4.1 | 4.6 | 5.5 | 7.3 | 9.1 | 11 | 12.8 | 14.8 |
Typical boring parameters for aluminum alloy
| Tool | Tool material | Milling speed (m/min) |
Feed rate (mm/r) |
Point angle (°) |
Helix angle (°) |
Secondary relief angle (°) |
Refrigerator |
| Replaceable boring cutter | High speed steel. | 25-40 | 0.2-0.3 | 140 | 30-20 | 8 | Water Soluble Coolant |
| Hard metal | 60-100 | 0.1-0.3 | 120 | 20-15 | 6 | Water Soluble Coolant | |
| Experimental Boring Cutter | High speed steel | 25-40 | 0.2-0.3 | – | 30-20 | 8 | Water Soluble Coolant |
| Hard metal | 60-100 | 0.1-0.3 | 20-15 | 6 | Water Soluble Coolant | ||
| Expandable boring mill | High speed steel | 20-30 | 0.3-0.6 | 60-120 | – | 6 | Water Soluble Coolant |
| Hard metal | 50-70 | 0.2-0.5 | 60-120 | 6 | Water Soluble Coolant | ||
| Flat bar | High speed steel | 25-40 | 0.05-0.6 | – | 30-20 | 12 | No refrigerant or water-soluble refrigerant |
| Hard metal | 60-100 | 0.05-0.6 | 20-15 | 10 | No refrigerant or water-soluble refrigerant |
Typical Flaring Parameters for Aluminum Alloy
| Tool | Tool material. | Chamfer (°). | Angle of attack (°). | Reaming speed (m/min). | The feed rate (mm/r) for the countersunk hole diameter (mm) is as follows: | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤10 | >10-25 | >25-40 | >40 | ||||||||
| Manual reamer. | High speed steel. | 45 | 40241 | / | / | / | / | / | |||
| Hard metal. | 45 | 40241 | / | / | / | / | / | ||||
| Stove. | High speed steel. | 30 | 0 | 40471 | 0.1-0.2 | 0.2-0.4 | 0.3-0.5 | 0.4-0.8 | |||
| Hard metal. | 30 | 0 | 20-50 | 0.2-0.3 | 0.3-0.5 | 0.4-0.7 | 0.5-1.0 | ||||
| Detour. | The allowable deviation (mm/r) of the countersunk hole diameter (mm) is as follows: | ||||||||||
| Insufficient diameter of the pre-drilled hole. | High speed steel. | ≤10 | >10-25 | >25-40 | >40 | ||||||
| Hard metal. | ≤0.2 | 0.1-0.3 | 0.1-0.3 | 0.2-0.5 | |||||||
| 0.06-0.1 | 0.1-0.2 | 0.1-0.3 | 0.2-0.4 | ||||||||
Note: The coolant used is a mixture of kerosene oil and turpentine (5:4), or mineral oil with a viscosity of about 33°E, or high-quality oil. The quality of dry milled holes is not very high.
