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FSW APPLICATION

Battery Trays Welded by FSW

Lightweight, crash-resistant aluminium battery casings with weld strength close to the base metal.

See FSW in action

water cooling plates

Why Choose Friction Stir Welding for Your Battery Trays Assembly?

Battery trays, also referred to as battery casings, are key structural components for electric and hybrid vehicles, railways and other industrial applications. Traditionally assembled using MIG/TIG welding, these enclosures are now increasingly manufactured with Friction Stir Welding (FSW) to achieve leak-tight joints, lightweight construction and outstanding crash performance. By using FSW, manufacturers gain technical advantages that directly improve safety, durability and cost-efficiency.

high crash resistance in battery trays

High Crash Resistance

FSW weld resistance is close to the base metal, allowing the weld to accept high plastic strain before failure.

no risk of leak in stiffened panels assembly

No Risk of Leak

Solid-state welding removes porosity, creating a sealed tray that protects internal components from external elements.

full aluminium battery trays

Full Aluminium

The battery tray is made of aluminium, resulting in a light, low-cost, fully recyclable tray with excellent heat transfer.

liquid cold plate welding

Superior Strength

FSW results in 2 times higher mechanical resistance compared to MIG or TIG. This results in a weight reduction of 10%.

FSW chill plate

Cost Divided by 10

FSW eliminates the need for filler material, shielding gas and extensive rework, making production far more cost-efficient.

Technical Specifications of FSW-Welded Battery Trays

battery tray design for FSW manufacturing

Battery trays can be manufactured using different processes depending on design complexity, production volume and performance requirements. Each manufacturing method offers specific advantages in terms of weight, cost and integration of functional features.

Fully extruded battery tray: Manufactured entirely from extruded aluminium profiles, this design offers excellent strength-to-weight ratio and uniform thermal performance. Ideal for lightweight applications with simpler geometries and high stiffness requirements.
Hybrid extrusion + die casting battery tray: Combines extruded profiles for structural sections with die-cast components for complex geometries. This approach balances weight reduction, design flexibility and cost efficiency, making it suitable for medium- to large-scale production.
Fully die-cast battery tray: Produced entirely through die casting, allowing the integration of complex shapes, mounting points and sealing features in a single part. Best suited for large series production where high geometric complexity is required.

1

FSW tool: Selecting the right FSW tool is crucial when welding battery trays. Tool dimensions, shoulder design, pin profile and the aluminium grade all directly affect weld penetration and quality. For battery trays, where both crash resistance and leak-tightness are critical, the tool must be carefully adapted to the geometry of each joint to guarantee repeatable results.

2

Design of the clamping jig: Proper clamping is essential to avoid gaps, distortion or misalignment during the welding of large battery trays. Given their size and complexity, dedicated clamping devices are required to maintain the flatness of extruded or die-cast components while following long weld seams. At Stirweld, we provide custom clamping solutions that secure the tray throughout the process, ensuring precision and defect-free welds.

3

Welding parameters: Battery tray performance depends on carefully tuned FSW parameters such as tool rotation speed, welding speed, Z-force and plunge depth. These settings influence the final strength of the joint as well as its sealing capacity. By carrying out prototyping trials, our engineers identify the optimal parameter window, resulting in robust welds that protect internal components and meet safety standards.

friction stir welding parameters for battery trays

custom liquid cold plate assembly

Metallographic cross-section

Cross-sectional analysis confirms the absence of porosity and incomplete penetration in FSW joints. For battery trays, this inspection ensures continuous sealing lines that are essential to protect the modules inside.

water cooling plates

Tensile test

Tensile testing measures the static strength of welded joints in accordance with ISO standards. In battery trays, it validates that welded seams can withstand mechanical loads and vibrations during vehicle operation.

thermal management technology

S-bending test

The S-bending test evaluates ductility by bending the weld to check its resistance to cracking. This test demonstrates the ability of battery tray welds to absorb deformation while maintaining integrity.

liquid cold plate test

Visual test

A visual inspection is performed to detect excessive flash and confirm correct tool pressure. Any irregularities may indicate potential weld defects.

See Friction Stir Welding Applied to Battery Trays in Real-Time

Comparing FSW to Traditional Battery Trays Assembly Techniques

Friction Stir Welding vs. TIG and MIG

Thermal control: Friction Stir Welding operates at lower temperatures compared to MIG or TIG welding, thereby reducing material distortion and warping. This is vital for maintaining the integrity of battery casings.

Joint quality: : FSW joints are often stronger and more durable, exhibiting enhanced fatigue resistance. The process also yields fewer defects, such as porosity or cracks, thereby improving the reliability of the joint.

No filler materials needed: Unlike MIG or TIG welding, FSW does not require filler materials (welding wire), simplifying the process and reducing costs.

Minimal material impact: Friction Stir Welding minimally impacts the microstructure of the material, which better preserves the mechanical properties of the original material.

tig mig welding

Aluminium Battery Trays: Key Concerns for Critical Sectors

Aluminium battery trays must meet strict requirements for safety, durability and thermal management. Their design and performance are especially critical in industries where reliability under heavy loads and demanding environments is non-negotiable.

friction stir welded battery casings in the automotive sector

Automotive

Lightweight trays for EVs ensure crash safety, long range and efficient thermal performance.

battery trays production for railways

Railways

Robust casings protect batteries in trains and metros, combining durability with low maintenance.

friction stir welding for e-mobilities manufacturing

Other e-Mobilities

From buses and trucks to construction and mining engines, aluminium battery trays provide safe housing, resistance to harsh environments and cost efficiency, supporting the electrification of heavy-duty vehicles.

They Trust Us

“FSW technology has the possibility that, when you weld, you don’t degrade the material as other process or other joining technologies. The main advantage that we see at Stirweld is the intercompability and the flexibility that the head provides us compared with a dedicated machine.”

customer testimonial stirweld

Mario Alberto Solís Alvarez

R&D Innovation Engineer

Dive Deeper: Comprehensive FSW Battery Trays Resources

Are you curious to learn more about Friction Stir Welding and battery casings? We provide everything you need, including webinars, blog articles and practical guides.

Webinar – 45 min – Replay on demand

Stiffened panels welded by FSW

Discover how friction stir welding is transforming the assembly of stiffened panels for demanding applications. This session highlights the specific behaviour of 6xxx aluminium alloys and addresses the challenges of welding high-strength 2xxx and 7xxx grades. Gain valuable insights from leading industry experts and learn how to enhance performance, reduce costs and secure reliable results in your projects.

Blog articles – 5 min

Friction Stir Welding: a key technology for the future of e-mobility

Stiffened panels welded by FSW

White paper – 20 min

5 essential steps to master Friction Stir Welding

Master the fundamentals of friction stir welding with our practical guide. In just five essential steps, you’ll learn how to design, set up and optimise your FSW process to achieve strong, defect-free welds.

Download for free now

thermal management - FSW liquid cold plate

White paper – 20 min

Aluminium stiffened panels welded by FSW

Dive deeper into the manufacturing of stiffened aluminium panels with friction stir welding. This resource explains how FSW delivers durable, high-quality joints while helping you solve common assembly challenges with confidence.

Download for free now

overcoming cold plate manufacturing challenges

Want to Cut Costs and Improve Battery Tray Assembly?

Friction Stir Welding ensures leak-tight, crash-resistant aluminium trays while reducing manufacturing costs. Contact our experts to optimise your assembly process.

Consult with an FSW expert