Qu'implique un post-traitement efficace du moulage sous pression?

In die casting production—whether for new energy vehicle motor housings or 5G base station cooling modules—post-processing of die casting is the final step that turns raw castings into high-performance, pièces prêtes à être commercialisées. Il corrige les défauts de moulage, optimise la qualité de la surface, et garantit que les pièces répondent aux normes de conception. Cet article détaille ses objectifs fondamentaux, processus clés, quality control methods, defect solutions, and cost-saving tips, helping you build a efficient post-processing workflow.

1. What Are the Core Goals and Principles of Die Casting Post-Processing?

Post-processing isn’t random—it follows clear goals and principles to avoid rework and ensure consistency.

1.1 Core Goals

The work focuses on four key objectives, tailored to part functions:

• Eliminate Casting Defects: Fix issues like shrinkage, pores, and flash left from casting.
• Optimize Surface Quality: Achieve smooth finishes or protective coatings for appearance and durability.
• Adjust Mechanical Properties: Boost strength, dureté, or creep resistance through heat treatment.
• Meet Design Accuracy: Ensure dimensions, platitude, and other specs match engineering requirements.

1.2 Guiding Principles

To prevent secondary damage and save time, two rules are non-negotiable:

• “Rough First, Then Fine”: Do heavy-duty work (like cutting sprues) d'abord, then precision tasks (like grinding). This avoids scratching finished surfaces.
• “Inside First, Then Outside”: Machine internal features (like holes) before external ones. Internal machining is more likely to cause minor deformation, which can be corrected when finishing the exterior.

2. What Are the Key Processes in Die Casting Post-Processing?

Post-processing has five core steps, each with specific techniques and parameters. Below is a detailed breakdown for industrial use:

2.1 Sprue, Riser, and Flash Removal

This step cleans up excess material from casting. The method depends on production volume and precision needs:

Note: Utiliser cold cutting for aluminum-magnesium alloys to avoid heat-affected zones that weaken the part.

2.2 Surface Treatment Combinations

Surface treatment improves appearance, résistance à la corrosion, et fonctionnalité. Choose based on material and part use:

2.3 Usinage de précision

This step refines dimensions and shapes. Success depends on clamping strategies and parameter optimization:

2.3.1 Clamping Strategies for Different Part Types

2.3.2 Optimized Machining Parameters

2.4 Heat Treatment Strengthening

Heat treatment boosts mechanical properties. Use material-specific schemes:

Critical Notes: Magnesium alloys need inert gas to avoid oxidation; Zinc alloys must not exceed eutectic temperature (causes melting).

2.5 Special Processing

For residual stress relief and sealing protection:

3. How to Control Quality in Die Casting Post-Processing?

Quality control ensures parts meet standards. Use the right tools and tests:

4. How to Fix Common Post-Processing Defects?

Defects like shrinkage or pores can be resolved with targeted solutions:

5. How to Control Costs and Cycles in Post-Processing?

Post-processing accounts for a large portion of total costs—optimize to save money and time:

6. Yigu Technology’s Perspective on Post-Processing of Die Casting

Chez Yigu Technologie, we see post-processing of die casting as the “value-adding bridge” between raw castings and high-quality parts. Our data shows 70% of part failures stem from rushed or mismatched post-processing—e.g., using heat treatment on porous aluminum parts causes cracking.

We recommend a “process-material matching” approach: For ADC12 aluminum alloy motor housings, we pair T6 heat treatment with precision boring to hit flatness <0.05mm/100mm; For Zamak5 zinc alloy medical handles, we use nano-chrome plating + laser engraving to meet ISO 10993 normes de biocompatibilité. By integrating automation (like AI inspection) and material-specific schemes, we help clients cut costs by 25% while improving part reliability.

7. FAQ: Common Questions About Post-Processing of Die Casting

Q1: Can all die casting materials use the same surface treatment?

Non. Par exemple, anodizing only works on aluminum alloys (it forms an oxide layer), while micro-arc oxidation is better for Al/Mg/Ti alloys. Zinc alloys are often electroplated for decoration, but powder coating works for most metals—always match the treatment to the material and part function.

Q2: Why is quench transfer time critical for aluminum alloy heat treatment?

Alliages d'aluminium (like A380) need fast quenching after solution treatment to trap strengthening elements. If transfer time exceeds 30 secondes, elements precipitate early, reducing tensile strength by up to 20%. We use automated quenching systems to keep transfer time <25 secondes.

Q3: How to reduce deformation in thin-walled die casting post-processing?

Use three methods: 1) Clamp with vacuum suction cups + honeycomb pads to spread pressure; 2) Use low cutting speeds (50-80m/min for aluminum) to minimize force; 3) Add a cryogenic treatment step (-196°C for 24h) to release residual stress before precision machining. These cut deformation by 60%.