Aluminium welding – from the single part to the small batch
stainlesstec welds aluminium for industrial and technically demanding applications. We make individual weldments as well as complex aluminium assemblies, combining welding with our own sheet metal work and finishing.
Welding aluminium takes experience: high thermal conductivity, a tough oxide layer and the differing behaviour of the various alloys place particular demands on preparation and process.
We make aluminium weldments to drawing and CAD data – as one-offs, prototypes, small batches or recurring assemblies. Typical work includes:
Enclosures and panelling
Frames and structures
Trays and vessels
Machinery and plant components
Brackets and consoles
lightweight load-bearing structures
components with high-quality visible surfaces
customer-specific custom work
complete welded aluminium assemblies
We can laser cut and bend the individual parts ourselves, then weld and finish them here.
Why welding aluminium takes particular experience
Aluminium behaves quite differently from stainless steel when welded.
High thermal conductivity
Aluminium conducts heat away from the weld zone very quickly. Heat input therefore has to be controlled and matched to material thickness, component geometry and alloy. At the same time the heat applied can cause considerable changes in shape – with thin-walled or large parts in particular, welding distortion has to be allowed for.
Oxide layer
Aluminium forms a natural oxide layer in air within a short time, and that layer has a far higher melting point than the metal beneath it. Proper preparation of the joint is therefore essential for a reliable weld.
Welding aluminium alloys – the material has a say
Aluminium is not simply aluminium: alloy, temper and the loads in service all affect weldability, strength, heat effects and the choice of filler metal. stainlesstec processes and welds the common weldable aluminium alloys and matches process and filler to base material and application, among them:
AlMg alloys
Aluminium-magnesium alloys such as AlMg3 (EN AW-5754) or AlMg4.5Mn (EN AW-5083) combine good weldability with high corrosion resistance. They are used for vessels, enclosures, machine components and demanding structures.
AlMgSi alloys
Alloys such as EN AW-6060, EN AW-6061 and EN AW-6082 are widely used for sections and structural parts. When welding, the alloy, its initial temper and the change in mechanical properties in the heat-affected zone have to be taken into account.
Pure and low-alloy aluminium
Pure aluminium and comparable low-alloy materials can also be welded and built into parts or assemblies, depending on the application.
High-strength and special aluminium alloys
With high-strength or specially alloyed aluminium we assess weldability project by project. Not every alloy is readily weldable – loss of strength, hot cracking tendency or metallurgical changes can be decisive for certain materials.
Filler metal to match the alloy
A reliable aluminium weld takes more than choosing the right process. The filler metal has to suit the base material and the application as well, with strength, corrosion resistance, resistance to hot cracking, any later surface treatment and service temperature all playing a part.
We therefore treat base material, filler metal and the loads in service as one system.
TIG welding of aluminium
TIG welding gives close control of the process and suits high-quality joints, thinner material and demanding weld geometries particularly well. Guiding the weld pool precisely produces a clean weld and good control of heat input.
We therefore use TIG above all on parts where weld quality, precision and appearance matter.
On suitable parts and thicknesses, MIG welding can offer advantages in welding speed and deposition rate, which makes it attractive for longer welds and the structures that carry them.
Which process is the better choice does not depend on economics alone: material thickness, geometry, access, weld requirements and the appearance sought all have to be considered together. We therefore choose the process to suit the job in hand.
Cleanliness is decisive when welding aluminium
A reliable aluminium weld depends on carefully prepared joints. Oxides, grease, oils and other contamination can impair both the process and the quality of the joint.
High-quality aluminium welding therefore begins with preparing and handling the parts correctly. On demanding work we carry that through the entire chain – from cutting and bending to welding.
Controlling distortion when welding aluminium
The high thermal conductivity and expansion of aluminium make handling welding distortion a central issue. Particularly with:
thin sheet
large areas
long welds
asymmetrical structures
parts with tight tolerances
design and welding process have to be matched to one another. We therefore allow for weld position, welding sequence, heat input, fixturing and structural stiffness.
The aim is not merely a good weld but a finished assembly that holds its dimensions.
Complete welded aluminium assemblies
Our strength is not confined to the individual joint: stainlesstec can make aluminium parts from the blank through to the complete welded assembly.
That lets us consider at the cutting stage how a part will later be bent and welded. Fits, joint locations and welding sequences can be aligned without coordinating several suppliers.
Low specific weight is one of the main reasons for choosing aluminium, which makes it particularly suitable where weight has to come down without giving up a technically robust solution.
That matters for machine components, moving parts, enclosures, vehicle technology, aerospace and other high-technology applications. What counts is matching design and process to the properties of the material chosen.
Visible welds and high-quality surfaces
On enclosures, panelling and other visible structures the weld is part of how the finished product looks. Weld finish and surface requirements then have to be considered together.
At the design stage it can already be decided where welds will run, which of them stay visible and which areas will be finished afterwards. That is how technical function and a high-grade finish come together.
Aluminium welding for demanding applications
We make aluminium weldments and assemblies above all for applications where low weight, precise manufacturing and reliable processing come together, among them:
Machinery and plant engineering
Enclosures, frames, covers and customer-specific machine components.
Aerospace and high technology
Lightweight components and custom work with high demands on precision, processing and documentation.
Defence technology
Aluminium components and assemblies to defined material and production specifications.
Special applications
Prototypes and designs for which standard parts do not fit the task.
Which material, testing or documentation requirements apply is settled for each project.
One-offs, prototypes and small aluminium batches
Not every demanding part is needed in large numbers. stainlesstec makes one-offs, prototypes, small batches and recurring welded aluminium assemblies.
With new designs in particular we can check before production starts whether joints, bends and welds are laid out for manufacture. Small design changes will often reduce welding effort and distortion while improving repeatability.
Let’s talk about your project.
Send us your drawing or CAD data by email – together with material, batch size and your requirements. We will come back to you with a sound assessment.
