ISO 25239: The essential standard for Friction Stir Welding of Aluminium

Aluminium is a key material in many industries, ranging from aerospace and automotive to shipbuilding. Among the various welding methods available, Friction Stir Welding has emerged as a revolutionary technique, offering high-quality welds with exceptional structural integrity. The ISO 25239 standard was specifically developed to regulate and standardize this innovative process. This standard plays a crucial role in defining clear guidelines and stringent requirements for the assembly of aluminium by FSW, thereby ensuring optimal performance and increased safety. Whether you are an engineer, a manufacturer, or a quality professional, this article will provide you with the essential knowledge to effectively adopt and apply the ISO 25239 standard in your aluminium FSW welding operations.

ISO 25239 The Essential Standard for FSW of Aluminium

Fundamentals of Friction Stir Welding: 4 Criteria to Achieving Quality Welds

To achieve a high-quality weld, it is essential to consider four specific criteria:

FSW tool geometry: an FSW tool consists of a shoulder that heats the materials through friction and a pin that stirs the parts to be welded together. The axial position of the tool is ensured by a universal attachment system, the Whistle Notch. This device provides optimal precision and stability during the welding process.

Welding parameters: to successfully perform and FSW operation, it is crucial to master the following parameters: tool selection, welding speed, rotation speed and vertical force.

Clamping tooling: FSW exerts high force on the parts to be welded, necessitating robust clamping tools to hold the parts in place and prevent any movement during the operation. Each part requires specific clamping tooling. We offer our expertise to design clamping solutions tailored to your needs.

Force control: to ensure weld quality, it is essential to maintain consistent tool penetration into the part being welded. Given that the surface of a part can present irregularities, force control in FSW is critical. This control allows for compensation of flatness variations and ensures a uniform and secure weld.

By considering these four criteria, you can optimize your FSW processes and guarantee quality welds according to the ISO 25239 standard.

ISO 25239: the Essential Standard for Reliable and Compliant FSW Welds

The ISO standard was developed to provide comprehensive guidelines and specific technical requirements for the FSW of aluminium.

Main objectives of the standard

The main objectives of ISO 25239 are:

Standardize FSW practice: provide common framework for FSW techniques, ensuring consistency and quality welds.

Ensure quality and safety: define rigorous quality criteria to minimize welding defects and guarantee the safety of welded structures.

Facilitate certification and compliance: help companies comply with international regulations and obtain the necessary certifications for their products.

Structure and content of ISO 25239

ISO 25239 is divided into several parts, each covering a specific aspect of the Friction Stir Welding process. Here are the main sections of the standard:

ISO 25239-1: Terminology. Definitions and technical terms used in the context of Friction Stir Welding.

ISO 25239-2: Design considerations. Recommendations for the design of FSW joints, considering material properties and manufacturing constraints.

ISO 25239-3: Qualification of operators and procedures. Qualification criteria for FSW machine operators and welding procedures, including qualification tests and required documentation.

ISO 25239-4: Quality and inspection. Inspection methods and quality critria for evaluating FSW welds, covering non-destructive testing techniques and acceptance standards.

ISO 25239-5: Equipment requirements. Specifications for the machines and tools used in FSW, including control systems and safety devices.

Impacts and benefits of the standard

Adopting ISO 25239 brings numerous significant advantages to companies. Firstly, it leads to a notable improvement in weld quality. By following clear and precise guidelines, companies can produce more reliable and durable welds, reducing the risks of defects and rework. This standardization of Friction Stir Welding process also results in substantial cost savings by reducing the expenses associated with rework and welding failures.

Additionally, ISO 25239 helps company comply with legal and industrial requirements. By adhering to these standards, they can more easily obtain the necessary certifications, facilitating access to new markets and ensuring essential regulatory compliance. This compliance enhances the credibility and trust of customers and business partners.

Furthermore, adopting ISO 25239 allows companies to increase their competitiveness in the global market. By adopting internationally recognized welding practices, they can demonstrate their commitment to quality and innovation, thereby differentiating themselves from the competition.

In summary, ISO 25239 represents a strategic tool for improving weld quality, optimizing production costs, ensuring regulatory compliance, and strengthening the competitive position of companies in the global market.

Technical and Quality Requirements

The ISO 25239 standard defines rigorous technical requirements and quality criteria for Friction Stir Welding of aluminium:

Technical Specifications

Welding Equipment: FSW machines must be precise and robust, with reliable force and position control systems.

Welding Tool: FSW tools should be made from wear-resistant and heat-resistant materials, with a design that allows for effective mixing and adequate penetration.

Welding parameters: Critical FSW parameters (rotation speed, travel speed, and vertical force) must be optimized according to the material and application.

Quality Criteria

Structural Integrity: Welds must be free from cracks and porosities, verified through destructive tests.

Visual Appearance: Welds should be free of visible defects.

Mechanical Properties: Welds must meet specific bending and tensile strenght requirements.

Tests and Certifications

Destructive tests: Include tensile and bending tests.

Certifications: Operators and welding procedures must be certified, ensuring they possess the necessary skills to comply with the ISO 25239 standard.

By following these requirements, companies can ensure high-quality FSW welds that meet international standards, ensuring the safety and durability of welded structures.

Why Adopted the ISO 25239 Standard?

Adopting the ISO 25239 standard offers numerous advantages for companies using the FSW process.

Improved Weld Quality

One of the most significant advantages of adopting the ISO 25239 standard is the improvement in weld quality. By following the standard’s clear and precise guidelines, companies can ensure stronger and more durable welds, thereby minimizing the risk of failure. The strict quality criteria and technical requirements ensure that each weld meets the highest standards, reducing the need for rework and post-weld adjustments.

Reduced Production Costs

Standardizing FSW processes leads to significant production cost reductions. By minimizing welding defects and rework, companies can save on materials, labor, and time. Moreover, using optimized welding parameters and suitable equipment increases operational efficiency, reducing downtime and increasing overall productivity.

Regulatory Compliance and Increased Competitiveness

Adopting the ISO 25239 standard helps companies comply with regulatory and industry requirements. Conformance to this international standard is often a prerequisite for obtaining necessary certifications and accreditations, facilitating access to new markets and customers. By demonstrating their commitment to quality and best practices, companies can enhance their reputation and competitive position.

Innovation and Continuous Development

The adoption of the ISO 25239 standard also encourages innovation and continuous development. By following standardized practices and integrating the latest technological advancements, companies can stay at the forefront of progress in the FSW field. This proactive approach fosters continuous improvement in processes and products, enabling companies to meet changing market and customer demands.

In Which Sectors Is the ISO 25239 Standard Essential?

The ISO 25239 standard is essential in sectors using FSW, particularly for aluminium assembly. This certification is crucial in industries where welding requirements are particularly high:

Automotive Industry: FSW is used for manufacturing body parts, chassis, battery trays, heat exchangers, and other components requiring lightness and robutness. This is particularly relevant in e-mobility, where ISO 25239 certification ensures the quality and safety of components.
Railway Industry: FSW is used to assemble components of trains, wagons, subways, and more.
Shipbuilding: Ship hulls, bridge structures, and other maritime components benefit from the ISO 25239 standard.
Aerospace Sector: This sector widely uses FSW to manufacture lightweight and strong components. ISO 25239 certification is essential to ensure the reliability of parts subjected to significant stresses.
Vacuum Industry: Achieving reliable vacuum seals is simplified with FSW, but quality standards are extremely high in this sector, making ISO 25239 certification essential for qualifying vacuum industry parts.

The ISO 25239 standard represents a significant advancement for the FSW industry. By offering clear guidelines and stringent technical requirements, this standard ensures high-quality, reliable, and compliant welds. Its adoption not only improves weld quality but also reduces production costs, ensures regulatory compliance, and enhances workplace safety. Furthermore, it encourages innovation and continuous development, enabling companies to remain competitive.

To effectively integrate the ISO 25239 standard into your welding operations and reap its numerous benefits, it is essential to follow the implementation steps described and draw inspiration from best practices and successful case studies.