Secondary Processing

After the die casting process, raw parts often contain unwanted excess material such as flash, gates, and sharp edges. To ensure quality, safety, and readiness for assembly or finishing, deburring and trimming are performed as early secondary processes.

🪚 Trimming

What it is :  

• The process of removing large excess metal sections from a die-cast part — such as sprues, runners, and flash that form around the parting lines or ejector pin locations.

How it's done :  

• Trimming Presses or manual tools  
• Custom trim dies used to shear excess material efficiently  
• Often performed immediately after casting while the part is still warm

Purpose :  

• To clean up the shape of the part  
• Prepare it for further processing (machining, finishing, etc.)

🛠️✨Deburring

What it is :

• Removing small, sharp burrs or residual rough edges left over after trimming, machining, or surface grinding

How it's done :

• Hand Tools (Blade, Files, Rotary Tools)
• Tumbling/vibratory machines for batch processing  
• Abrasive wheels, brushes, or Air tool

Purpose :  

• Improve part safety and handling  
• Ensure dimensional accuracy and a clean look  
• Enhance sealing surfaces and part fit in assembly  
• Prepare the surface for coating, plating, or painting

🛠️ Why It Matters  

Without trimming and deburring, cast parts can pose assembly issues, safety risks, and poor surface finish.

At ZincAlu, we ensure all parts are processed to meet both functional and cosmetic expectations — right from the start.

For customer which requires further cosmetic enhancement or improved surface protection, there are choices of method including:

Shot blasting :

• Removes oxide layers, sand, flash, or residual casting debris
• Improves surface texture for better paint, powder, or plating adhesion
• Slightly hardens the surface (shot peening effect), improving fatigue resistance
• Provides a uniform matte finish for cosmetic or functional purposes

Tumbling :

• Remove fine burrs, flash & oxide layers
• Prepare parts for coating, assembly or inspection
• Uniform smooth Surface finish

Wet paint/Powder Coating/ED Coating/Anodizing/Chemical Conversion :

Applying aesthetic color, gloss levels

Offers chemical & physical protection

Buffing :

Buffing is a fine polishing process that enhances the surface appearance and smoothness of a part.

Polishing :

Extra fine surface process which offer smoothness, reflectivity & cleanliness of metal.

🧪 Leak Testing & Impregnation  

At ZincAlu, we offer in-house leak testing and impregnation services to meet strict customer requirements for pressure-tightness and performance. These processes are especially important for components used in automotive, HVAC, hydraulic, and electronics applications.

Applications:  

• Components for fluid handling (e.g. pumps, valves, covers)  
• Castings with internal cavities or sealing surfaces  
• Parts with threaded or machined ports

Capability :

Our leak test Facility is able to test up to 20Bar

🛡️ Impregnation

Purpose:

To seal microporosity in castings that could cause fluid leakage or affect pressure containment. This process does not affect dimensions or mechanical properties.

Process Used:  

• Vacuum impregnation with a resin (often anaerobic or polymer-based)  
• Resin fills the pores and hardens, permanently sealing internal voids  
• Parts are then cleaned, cured, and tested

When to Use It:  

• Cast parts that must be pressure-tight but show porosity on x-ray or leak test  
• Parts requiring post-machining sealing before coating or assembly

🔍 Benefits to Your Product:

• Improved reliability in the field  
• Extended service life for pressure-sensitive parts  
• Compliance with quality standards for sealed components  
• Reduced scrap and rework due to porosity-related failures

We support sub-assemblies for Plug, Nuts, Bolts & Fitting Components. 

Many of the post-casting secondary processes are labor-intensive and highly dependent on skilled workers. 

At ZINCALU, we have proactively investing on machines, tools & people to integrate automation. We have been studying, designing and setting up semi-automation line for suitable products.