Qu'est-ce qui rend l'usinage par réduction de surface CNC indispensable pour la fabrication de précision?

Dans la fabrication de précision moderne, from automotive engine blocks to aerospace titanium alloy frames, CNC surface reduction machining stands out as a core process. Unlike ordinary rough machining that prioritizes speed, it focuses on controlled material removal to achieve exact geometries, précision dimensionnelle, and surface integrity. Cet article détaille ses objectifs fondamentaux, key implementation steps, parameter controls, and practical applications to help you master this critical technique.

1. What Are the Core Goals of CNC Surface Reduction Machining?

The primary value of this process lies in “correction” and “optimization” rather than just material removal. Below are its four core objectives, organized by practical priority:

2. How to Choose Equipment and Tools for CNC Surface Reduction Machining?

La bonne adéquation des machines-outils et des outils affecte directement la précision et l'efficacité du traitement. Vous trouverez ci-dessous un guide détaillé pour différents types de pièces:

2.1 Machine Tool Selection Based on Workpiece Size

2.2 Tool Selection Based on Material Characteristics

3. What Programming Strategies Optimize CNC Surface Reduction Machining?

Poor programming leads to tool marks, uneven cutting loads, and low efficiency. Ci-dessous sont 4 Stratégies d'optimisation prouvées:

1. Spiral Progressive Cutting Depth

Replace vertical up/down tool entry with spiral feeding (helix angle: 10-15°). This reduces cutting impact by 40% and avoids sudden tool breakage.

2. Reasonable Overlap Rate Setting

Maintain an overlap rate of 15%-30% between adjacent toolpaths. Par exemple, un 20% overlap for a φ 10mm cutter ensures no uncut areas and smooth surface transitions.

3. Island Boss Path Planning

For workpieces with island bosses (Par exemple, culasses de moteur), use loop cutting (from outside to inside). This balances tool load (fluctuation ≤ 10%) and prevents tool deflection.

4. Cycloidal Tool Path Generation

Utiliser le logiciel CAM (Par exemple, et, Mastercam) to generate cycloidal paths. This reduces tool marks by 60% compared to linear paths and improves surface roughness from Ra 1.6μm to Ra 0.8μm.

4. How to Control Process Parameters for High-Quality Results?

Parameter mismatches are the top cause of defects (Par exemple, surface burns, dimensional deviations). Below is a parameter guide for common materials:

4.1 Key Parameters for Different Materials

4.2 Cooling Strategy for Difficult-to-Machine Materials

For stainless steel or titanium alloy, increase cooling fluid flow to 15-20 L/min (using chlorine-containing extreme pressure additives). This reduces cutting temperature by 50°C and prevents work hardening.

5. How to Prevent Deformation and Ensure Quality?

Thin-walled parts and high-hardness materials are prone to deformation. Ci-dessous sont 3 critical quality assurance measures:

5.1 Stress Deformation Prevention for Thin-Walled Parts

• Use layered cutting: Each depth of cut ≤ 20% of wall thickness (Par exemple, 0.4mm max for a 2mm thick part).
• Separate roughing and finishing: Add an aging process between them to release internal stress (réduit la déformation par 70%).
• Optimize clamping: Use a multi-point support fixture (support area ≥ 80% of workpiece bottom) to avoid single-point stress concentration.

5.2 Geometric Tolerance Inspection

• Use a magnetic base dial indicator (précision: 0.001MM) for multi-point flatness checks (≥ 5 measurement points per m²).
• For large surfaces, detect diagonal height differences (max allowable: 0.03mm / m) Pour éviter la déformation.
• Utilisez une machine à mesurer de coordonnées (Cmm) for full-profile inspection of precision parts (detection accuracy: ± 0,002 mm).

6. Yigu Technology’s Perspective on CNC Surface Reduction Machining

À la technologie Yigu, Nous voyons CNC surface reduction machining as a “precision correction tool” rather than a simple cutting process. Our data shows that 60% of precision part failures stem from improper machining strategies—for example, using linear tool paths on thin-walled parts causes 30% more deformation than cycloidal paths.

We recommend integrating machining requirements into the early design stage: For auto engine blocks, we combine PCD cutters with spiral cutting to achieve Ra 0.4μm surface roughness; for aerospace titanium frames, we use gantry machines with multi-point clamping to control flatness within 0.02mm/m. By balancing efficiency and precision, we help customers reduce rework rates by 25% et améliorer l'efficacité de la production en 30%.

7. FAQ: Common Questions About CNC Surface Reduction Machining

T1: Can CNC surface reduction machining correct pre-process errors?

Oui. It can fix errors like uneven thickness (up to 0.1mm) or local dents from casting/forging. Par exemple, it can repair 0.05mm deep dents on mold parting surfaces to restore sealing performance.

T2: What’s the difference between CNC surface reduction and ordinary rough machining?

L'usinage grossier ordinaire donne la priorité à la vitesse d'enlèvement de matière (taux d'élimination ≥ 100 cm³/min) avec une faible précision (tolérance: ± 0,1 mm). Réduction de surface CNC se concentre sur la précision (tolérance: ± 0,01 mm) et qualité de surface (Ra ≤ 0.8μm), avec un taux d'élimination plus lent (10-50 cm³/min).

T3: How to handle high-hardness quenched steel (HRC ≥ 50) in this process?

Utiliser la technologie de coupe assistée par vibration (fréquence des vibrations: 20-50 khz) pour réduire la force de coupe de 40%. Associez-le au CBN (nitrure de bore cube) outils (dureté: CRH 70-80) pour éviter l'usure des outils et assurer l'état de surface.