Range anxiety is a weight problem. As a premier automotive die casting parts manufacturer, Sureton explores the metallurgy and process controls required to produce crash-relevant structural parts (shock towers, battery trays) that replace steel.
In the Electric Vehicle (EV) race, Weight is the Enemy.
Every added kilogram increases energy consumption, requiring a larger battery pack to maintain range. This initiates a vicious cycle of added weight, cost, and complexity. The engineering mandate is therefore unequivocal: integrate and lightweight by replacing multi-part steel assemblies with single-piece aluminum castings.
However, this isn’t just about swapping materials. It requires a fundamental shift in manufacturing technology. You cannot produce a crash-relevant shock tower using the same process as a toaster oven cover.
At Sureton, we are evolving from a traditional caster to a specialized Automotive die casting parts manufacturer. Here is the technical breakdown of how we achieve high-strength, high-ductility structural parts for the EV era.
The Challenge: Why Standard Die Casting Fails
Standard High-Pressure Die Casting (HPDC) using alloys like ADC12 or A380 is fantastic for rigid housings, but it has a fatal flaw for structural automotive applications: Brittleness.
Gas Porosity: Standard HPDC traps air.
No Heat Treatment: If you try to heat treat (T6/T7) a standard die-cast part to increase strength, the trapped gas expands, causing surface blisters and warping.
Low Elongation: Standard alloys have an elongation of < 3%. In a crash event, they snap. Structural parts need to bend and absorb energy (Elongation > 10%).
To solve this, we employ Structural Die Casting.
1. The Metallurgy: Beyond ADC12
For structural parts (like subframes, B-pillars, or shock towers), we abandon standard scrap-based alloys. We use Primary Low-Iron Alloys (e.g., AlSi10MnMg or Silafont®-36 equivalent).
Iron Content: Controlled to < 0.18% (vs. ~1.0% in ADC12) to minimize the formation of brittle iron-intermetallic phases.
Manganese (Mn): Added to prevent die soldering since we removed the iron.
The Result: A material capable of achieving elongation rates >10% (characteristic of wrought alloys) while retaining the design freedom and integration potential of a complex casting.
2. The Process: High-Vacuum & Thermal Control
To make these parts weldable and heat-treatable, we must eliminate gas.
High-Vacuum Die Casting (HVC): We employ systems capable of evacuating the cavity to < 20 mbar before injection. This near-absolute vacuum is critical to achieving the pore-free microstructure necessary for subsequent heat treatment and welding.
Laminar Flow: We design gate runners to minimize turbulence. We want the metal to push the air out, not mix with it.
3. Heat Treatment: T6 vs. T7
Once cast, the part is not finished. The magic happens in the furnace.
T6 (Solution + Artificial Aging): Maximizes Strength. Used for parts that need to carry heavy static loads but don’t need to deform much.
T7 Temper (Solution + Over-Aging): Prioritizes ductility, dimensional stability, and corrosion resistance. By controllably coarsening the strengthening precipitates, we achieve an optimal balance for crash energy absorption while minimizing the risk of distortion in large, thin-walled castings.
F-Temper (As Cast): For newer alloys (like AlMg5), we can achieve structural properties without heat treatment, avoiding the risk of thermal distortion. This is a major cost-saver for large components like battery trays.
4. Beyond the Chassis: Thermal Management
Lightweighting isn’t limited to the body-in-white. It extends to the thermal systems.
As EVs adopt more powerful matrix lighting and autonomous driving sensors, heat dissipation becomes critical. We apply similar thin-wall, high-density casting techniques to produce Aluminum die casting for LED housing and ADAS heatsinks.
The Goal: Maximize surface area (cooling fins) while minimizing weight.
The Tech: Using high-fluidity alloys to cast fins as thin as 1.0mm, replacing heavy extruded assemblies.
5. Joining Technologies: SPR and Welding
Structural castings must connect to the rest of the car. Unlike standard die castings, Sureton’s structural parts are designed for modern joining methods:
Self-Piercing Riveting (SPR): Our high-ductility parts won’t crack when a rivet is driven through them.
Laser Welding: Because we use high-vacuum to minimize gas, our parts can be welded to extruded profiles without porosity blowouts in the weld seam.
Engineering the Structural Future
The shift to EVs is rewriting the rules of manufacturing. The evolution towards electric drivetrains demands a parallel evolution in vehicle architecture. High-integrity, structural die castings are not just an option; they are a foundational technology for achieving the necessary integration, lightweighting, and performance. Success requires a partner whose expertise spans from metallurgy to manufacturing.
Partner for the Structural Shift.
Transitioning from steel assemblies to high-integrity aluminum castings requires a partner with expertise spanning from metallurgy to manufacturing validation. Sureton’s Automotive Team supports this with material property databases, FEA-coupled process simulation, and a track record of component-level validation.
Ready to engineer your lightweight solution? Let’s discuss how to apply structural die casting to your next chassis or battery enclosure design.
