Dans Usinage CNC, why do two shops produce aluminum parts with the same machine—one getting smooth surfaces and long tool life, the other facing frequent tool breaks and rough edges? The answer lies in mastering parameters of CNC processing aluminum. Aluminum’s soft, ductile nature makes it easy to machine, but wrong settings (Par exemple, too slow a cutting speed or too deep a cut) waste time, outils de dommage, and ruin parts. Cet article décompose 6 core parameters, sélection d'outils, cooling strategies, Exemples du monde réel, and common mistakes to avoid, helping you achieve flawless aluminum machining.
Why Aluminum CNC Processing Needs Specialized Parameters
Aluminium (and its alloys like 6061-T6, 7075-T6) isn’t like steel or titanium—it has unique traits that demand tailored parameters:
- Dureté faible: Aluminum’s Brinell hardness (HB 25–100) means it can be cut at high speeds, but softness also causes “built-up edge” (ARC)—molten aluminum sticks to the tool, ruining surface finish.
- Haute conductivité thermique: Aluminum transfers heat 5x faster than steel. Without proper cooling, heat damages tools and warps thin-walled parts.
- Ductilité: Aluminum produces long, stringy chips that can clog machines if chip evacuation parameters are off.
These traits mean aluminum needsVitesses de coupe élevées, optimized feed rates, eteffective cooling—parameters that would fail for harder materials.
6 Core Parameters of CNC Processing Aluminum
The following parameters are the “engine” of successful aluminum machining. Each directly impacts efficiency, qualité, and tool life—use the tables and tips to fine-tune them:
1. Vitesse de coupe (Vc)
Cutting speed is the speed of the tool’s cutting edge relative to the workpiece (measured in m/min). It’s the most critical parameter for aluminum—too slow causes BUE; too fast overheats tools.
| Matériau à outils | Vitesse de coupe recommandée (m / mon) | Raisonnement clé | Ideal Alloys |
|---|---|---|---|
| Outils en carbure | 200–800 | Carbide’s high heat resistance handles aluminum’s fast cutting; TiAlN-coated carbide works best (reduces BUE). | – 6061-T6: 300–600 m/min (balanced for speed/quality)- 7075-T6: 200–500 m/min (harder alloy needs slower speed) |
| HSS Tools | 50–150 | HSS can’t handle high heat—slower speeds prevent tool softening. | Alloys for low-precision parts (Par exemple, 1100-H14, 3003-H14). |
Pour la pointe: For large workpieces (Par exemple, 1m aluminum plates), start at the lower end of the range (300 m / mon) Pour éviter les vibrations; pour petites pièces (Par exemple, 10mm brackets), use higher speeds (600–800 m/min) Pour gagner du temps.
2. Taux d'alimentation (Fz & F)
Feed rate has two key metrics:
- Alimentation par dent (Fz): The distance the tool moves per tooth (mm/dent)—controls chip thickness.
- Total Feed Rate (F): The overall tool movement speed (mm / min)—calculated as
F = N × z × Fz(N = spindle speed, z = number of tool teeth).
| Type d'usinage | Alimentation par dent (Fz, mm/dent) | Total Feed Rate (F, mm / min) | Impact clé |
|---|---|---|---|
| Brouillage | 0.1–0,3 | 500–3 000 | Faster feed removes material quickly; thicker chips reduce BUE. |
| Semi-finisse | 0.05–0,2 | 300–1 500 | Balances speed and surface finish; Évite l'accumulation de puces. |
| Finition | 0.02–0,1 | 100–800 | Slow feed creates smooth surfaces (Rampe < 1.6 µm); critical for visible parts. |
Exemple: A carbide end mill (z=4 dents) usinage du 6061-T6 à N=5.000 tr/min avec Fz=0,2 mm/dent → Avance totale F = 5,000 × 4 × 0.2 = 4,000 mm / min.
3. Profondeur de coupe (Ap)
La profondeur de coupe est la distance à laquelle l'outil pénètre dans la pièce. (MM). Il équilibre le taux d'enlèvement de matière et la charge de l'outil : la douceur de l'aluminium vous permet d'utiliser des profondeurs plus grandes que l'acier..
| Type d'usinage | Profondeur de coupe (Ap, MM) | Objectif clé | Considération de l'outil |
|---|---|---|---|
| Brouillage | 2–5 | Retirez rapidement 80 à 90 % de l’excédent de matériau; minimiser le nombre de passes. | Utiliser des outils puissants (Par exemple, 10fraises en carbure de diamètre mm) gérer la charge. |
| Semi-finisse | 0.5–2 | Surfaces rugueuses lisses; Préparez-vous à la finition (laisser un minimum de matière pour la coupe finale). | Outils de taille moyenne (Par exemple, 6diamètre mm) équilibre précision et vitesse. |
| Finition | 0.1–0,5 | Atteindre les dimensions finales et la finition de surface; éviter de surcouper. | Pointu, high-precision tools (Par exemple, 4mm diameter TiAlN-coated end mills). |
Avertissement: For thin-walled aluminum parts (Par exemple, 1mm thick enclosures), limit Ap to 0.1–0.3 mm—too deep a cut causes warping.
4. Vitesse de broche (N)
Vitesse de broche (RPM) is the rotational speed of the tool. It’s tied to cutting speed via the formulaN = (1000 × Vc) / (π × D) (D = tool diameter, MM).
| Diamètre de l'outil (D, MM) | Vitesse de broche (N, RPM) (for Vc=400 m/min) | Note clé |
|---|---|---|
| 3 | 42,441 | Small tools need high speeds—use dynamic balancing to avoid vibration. |
| 6 | 21,220 | Medium tools: Balance speed and stability; use coolant to reduce heat. |
| 12 | 10,610 | Large tools: Lower speeds prevent tool chatter; check collet tightness. |
| 20 | 6,366 | Extra-large tools: Utilisez des vitesses lentes (5,000–8,000 rpm) pour la sécurité. |
Exemple du monde réel: A 6mm carbide tool machining 6061-T6 at Vc=400 m/min → N = (1000×400)/(3.14×6) ≈ 21,220 RPM. This speed removes material fast without overheating.
5. Refroidissement & Lubrification
Aluminum’s high thermal conductivity means cooling isn’t optional—it prevents tool damage and BUE.
| Méthode | Caractéristiques clés | Applications idéales |
|---|---|---|
| Water-Based Coolant | – High heat dissipation (cools 2x faster than oil).- Faible coût; facile à nettoyer. | Usinage à volume élevé (Par exemple, automotive aluminum parts); roughing/semi-finishing. |
| Oil-Based Coolant | – Réduit la friction (prevents BUE better than water).- Améliore la finition de la surface. | Precision finishing (Par exemple, visible aluminum enclosures); thin-walled parts. |
| Coupure à sec | – No coolant needed; reduces cleanup.- Only works with sharp, outils revêtus. | Petit lot, pièces à faible précision (Par exemple, prototypes); avoid for large cuts. |
Pour la pointe: Pour finir, mix 5–10% oil-based lubricant into water-based coolant—it combines heat dissipation with BUE prevention, creating mirror-like surfaces (Rampe < 0.8 µm).
6. Sélection d'outils (Matériel & Géométrie)
Even perfect parameters fail with the wrong tool. Aluminum needs tools that resist BUE and cut cleanly.
| Tool Feature | Recommendation for Aluminum | Avantage clé |
|---|---|---|
| Matériel | – Carbure (TiAlN or TiCN-coated): Best for high speeds.- Céramique: For extreme speeds (800+ m / mon) on soft alloys. | – TiAlN coating repels aluminum (reduces BUE).- Ceramic handles heat without wear. |
| Géométrie | – Angle de râteau positif (10°–20°): Réduit la force de coupe; minimizes BUE.- Bords de coupe pointus: Cleanly shears aluminum (avoids tearing).- Wide chip grooves: Prevents chip clogging. | – Positive rake angle makes cutting easier—ideal for soft aluminum.- Sharp edges improve surface finish. |
Éviter: HSS tools for high-volume work—they wear out 5x faster than carbide when cutting aluminum at 300+ m / mon.
Parameter Table for Common Aluminum Alloys (6061-T6 & 7075-T6)
Use this ready-to-use table to start machining—adjust based on your machine’s capacity and tool specs:
| Paramètre | 6061-T6 (Brouillage) | 6061-T6 (Finition) | 7075-T6 (Brouillage) | 7075-T6 (Finition) |
|---|---|---|---|---|
| Vitesse de coupe (m / mon) | 300–600 | 500–800 | 200–500 | 400–700 |
| Alimentation par dent (mm/dent) | 0.1–0,3 | 0.02–0,1 | 0.08–0,25 | 0.01–0,08 |
| Profondeur de coupe (MM) | 2–5 | 0.1–0,5 | 1.5–4 | 0.1–0.4 |
| Vitesse de broche (RPM) | 3,000–10 000 | 5,000–15 000 | 2,500–8 000 | 4,000–12 000 |
| Méthode de refroidissement | Water-based coolant | Oil-water mix | Water-based coolant | Oil-water mix |
Cas réel: Machining 6061-T6 Aluminum Enclosures
- Problème: A consumer electronics firm needed 1,000 boîtiers en aluminium (100mm×50mm×2mm) avec:
- Finition de surface: Rampe < 1.6 µm (visible, pas de rayures).
- Temps de production: < 2 minutes par partie.
- Vie de l'outil: > 500 parts per end mill.
- CNC Solution:
- Outil: 6mm TiAlN-coated carbide end mill (z=4 dents).
- Paramètres: Vc=500 m/min, Fz=0.15 mm/tooth, Ap=0.3 mm (finition), N=26,535 rpm.
- Refroidissement: 8% oil-water mix (prevents BUE, cools tool).
- Résultat:
- Finition de surface: Ra=1.2 μm (meets requirement).
- Temps de production: 1.8 minutes par partie (beats target).
- Vie de l'outil: 620 parts per end mill (reduces tool costs by 20%).
Common Mistakes & Comment les réparer
Even experts mess up aluminum parameters—here’s how to solve 3 frequent issues:
- Built-Up Edge (ARC) on Tool
- Cause: Too slow cutting speed (Vc < 200 m / mon) or dry cutting.
- Réparer: Increase Vc by 50–100 m/min; add oil-based lubricant to coolant.
- Chatter/Vibration
- Cause: Too high spindle speed for large tools (Par exemple, 20mm tool at 10,000 RPM) or loose clamping.
- Réparer: Reduce N by 20–30%; use a stronger clamp (Par exemple, hydraulic vise) pour sécuriser la pièce.
- Warped Thin-Walled Parts
- Cause: Too deep a cut (Ap > 0.3 MM) or uneven cooling.
- Réparer: Limit Ap to 0.1–0.2 mm; use a coolant nozzle directed at the cutting area (ensures even cooling).
Perspective de la technologie Yigu
À la technologie Yigu, Nous voyonsparameters of CNC processing aluminum as the key to unlocking aluminum’s full potential. Nos machines CNC (YG-6000 series) are optimized for aluminum: they have high-speed spindles (jusqu'à 24,000 RPM) for fast cutting, and smart coolant systems that auto-adjust flow based on Vc and Ap. We’ve helped clients cut aluminum machining time by 35% and extend tool life by 40%—from automotive part makers to electronics firms. As aluminum use grows in lightweight designs, we’re adding AI parameter optimization to our software—soon, it will auto-suggest settings based on your alloy and part, making flawless machining accessible to everyone.
FAQ
- Q: Can I use the same parameters for 6061-T6 and 7075-T6?UN: No—7075-T6 is 30% harder than 6061-T6. Reduce Vc by 20–30% and Fz by 10–20% for 7075-T6 to avoid tool wear. Par exemple, if 6061-T6 uses Vc=500 m/min, 7075-T6 should use Vc=350–400 m/min.
- Q: What’s the best coolant for aluminum finishing?UN: A 5–10% oil-water emulsion (Par exemple, huile minérale + eau) Fonctionne mieux. It cools like water and lubricates like oil—preventing BUE and creating smooth surfaces. Avoid pure water (causes BUE) or pure oil (mauvaise dissipation de la chaleur).
- Q: How do I calculate spindle speed for a custom tool diameter?UN: Utilisez la formule
N = (1000 × Vc) / (π × D). Par exemple, a 8mm tool machining 6061-T6 at Vc=400 m/min → N = (1000×400)/(3.14×8) ≈ 15,924 RPM. Most CAM software (Par exemple, Mastercam) calculates this automatically.