Precision Machining of Automotive Headlight Mold Cores
Critical Processes for Optical-Quality Surface Finish
1. Material Selection
Key Requirements:
- High-Strength Tool Steel
- Common grades: DIN 1.2344 (H13), 1.2738 (P20+Ni)
- Hardness: 48-52 HRC after heat treatment
- Corrosion Resistance
- Essential for humid operating conditions
- Preferred: Stainless variants like NAK80
2. Core Machining Process Flow
Step-by-Step Manufacturing:
1. Rough Machining
- 3-axis CNC milling removes 90% material
- Cutting parameters:
- Feed rate: 800-1200 mm/min
- Depth of cut: 2-3 mm
- Leave 0.5mm allowance for finishing
2. Heat Treatment
- Vacuum hardening to 1000-1050°C
- Double tempering at 550-600°C
- Achieve uniform hardness ≤±1 HRC variation
3. Precision Finishing
- 5-axis CNC machining:
- Tolerance: ±0.005mm
- Surface roughness: Ra 0.2-0.4μm
- Critical features:
- Light guide grooves (0.1-0.3mm wi…