TIG welding aluminum with Minarc T

L'ABC du soudage

How to weld aluminum

7 mai 2024

Some metals, like aluminum, have a naturally occurring, tough surface oxide layer. That surface oxide layer must be removed to enable successful welding. In the case of aluminum alloys, the surface oxide layer has a significantly higher melting temperature (approximately 2000°C) than the melting temperature of the aluminum base material (660°C).

Antti Kahri

With TIG (Tungsten Inert Gas) welding, the tough surface oxide is typically broken down and dispersed using alternating current (AC). This is because DC- welding (Direct Current, negative polarity), which has good penetration characteristics, doesn’t provide enough heat to remove the oxide layer, and it doesn’t have a cleaning effect on the weld pool like DC+ welding (Direct Current, positive polarity) does. On the other hand, DC+ delivers too much heat to the electrode and causes it to melt, which is not wanted in TIG welding. Unlike aluminum, for example, carbon steels, stainless steels, copper, and titanium can be welded using DC-.

AC TIG welding

During the AC TIG welding process (Figure 1), the arc burns between a tungsten electrode and the workpiece, protected from atmospheric contamination by an inert gas shield (typically, the shielding gas used is commercial-grade pure Argon). As the welding arc ignites and burns, the high temperature of the tungsten electrode ionizes the argon atoms within the argon shielding gas column. The resulting reciprocating, negatively charged electrons, and positively charged ions, together with the AC (alternating positive and negative half-cycle current waveform), break down the aluminum surface oxide, establishing a controlled welding process that has an optimal balance of cleaning effect, heat input, and penetration.

Figure 1. AC TIG welding of the aluminum corner joint. This figure shows the DC- phase of the process that gives the weld its penetration.

Pulsed MIG welding

In MIG (Metal Inert Gas) welding, the wire electrode is melted so DC+ can be utilized. This means that there is enough heat in every typical MIG welding process to remove the aluminum oxide layer. To ensure the best possible welding quality, like in AC TIG welding, the oxide layer and weld pool should be dispersed while welding. In MIG welding, this can be done most efficiently by using a pulsed current (pulsed MIG welding, Figure 2). The variation of welding current helps to keep the process stable and to achieve high-quality, clean welds that are free from porosity. This effect can be taken even further by using stepping movement while welding or by using double pulse welding. In double-pulse welding, the wire feed speed is also pulsed, and this increases the stirring effect in the weld pool.

Figure 2. Pulsed MIG welding detaching a droplet from 1,2 mm AlMg5 filler wire.

The best portable welding machines for Aluminum

A good TIG welding solution for aluminum is the Minarc T 223 ACDC. It’s an entirely new 220 A, 1-phase, multi-voltage 220V-240V / 110V-120V, AC/DC TIG, and MMA welding machine that includes an electrolytic weld cleaning process as standard. Now, in seconds, you can weld and electrolytically clean your perfect welds with one machine. Another portable welding machine that is perfect for aluminum MIG welding is the Master M 205. It stands out from most of the other 1-phase MIG welding machines because it offers a professional-level pulse welding process.

Antti Kahri
Author

Antti Kahri

Welding Engineer, Welding Team at Kemppi Oy. International Welding Engineer (IWE) who has more than ten years of experience developing welding characteristics for TIG, MIG/MAG and MMA welding machines, such as X8 MIG Welder and MasterTig. Passionate about finding user-friendly ways to improve the quality and efficiency of welding.

Plus d'articles de blog

Soudage pulsé de haute qualité avec un poste à souder MIG/MAG monophasé

Soudage pulsé de haute qualité avec un poste à souder MIG/MAG monophasé

La polyvalence des équipements de soudage portables a toujours été limitée par l’absence de soudage MIG/MAG pulsé. Il a été avancé qu’une alimentation triphasée était nécessaire pour obtenir un soudage MIG/MAG pulsé de haute qualité.

Soudage manuel

What is pulsed MIG welding, and for what you can use it?

What is pulsed MIG welding, and for what you can use it?

Pulsed MIG/MAG welding is a significant improvement in welding technology, offering accuracy, productivity, and flexibility that conventional welding methods can hardly compete with. This advanced process has become popular for professionals looking to improve weld quality, especially in demanding applications. Here's a closer look at how pulsed MIG/MAG welding works and the situations where it truly shines.

L'ABC du soudage

What to consider when buying a welding machine?

What to consider when buying a welding machine?

Once a welding machine has reached the end of its life cycle, or a company expands its operations, it's time to find a new best friend for the welder. There is a wide range of welding machines on the market, and in many cases, comparing different brands and models is challenging. What kind of things should be considered when purchasing a welding machine?

L'ABC du soudage

How does steel welding benefit from special processes?

How does steel welding benefit from special processes?

Welding mild steels may often be considered a simple task. However, welding these steels has specific characteristics that can make the welding process challenging.

Soudage manuel, L'ABC du soudage

New Kemppi Robotics Team

New Kemppi Robotics Team

Achieving strategic goals and enhancing customer experience

Les personnes

Comment choisir sa torche de soudage MIG/MAG

Comment choisir sa torche de soudage MIG/MAG

Le soudage MIG/MAG est l'un des procédés de soudage les plus courants et les plus polyvalents. Il est utilisé pour diverses applications, telles que l'automobile, la construction, la fabrication et la maintenance. Cependant, il est essentiel de choisir une torche de soudage adaptée à votre travail pour obtenir des résultats optimaux.

Soudage manuel, L'ABC du soudage

Inscrivez-vous à notre newsletter et soyez parmi les premiers à découvrir les dernières actualités de Kemppi.

En vous abonnant, vous acceptez de recevoir des e-mails marketing de Kemppi.

Le précurseur du soudage à l'arc

Kemppi s’impose comme le leader en matière de conception dans l’industrie du soudage à l'arc. Grâce à l'optimisation continue de l'arc de soudage, nous nous engageons à améliorer la qualité et la productivité du soudage, tout en œuvrant pour un monde plus respectueux de l'environnement et plus équitable. Kemppi propose des produits durables, des solutions numériques et des services destinés aux professionnels, qu'il s'agisse de grandes entreprises industrielles ou d’entrepreneurs. La fiabilité et la simplicité d'utilisation de nos produits sont au cœur de notre philosophie. Fort d’un réseau de partenaires hautement qualifiés dans plus de 70 pays, nous rendons notre expertise accessible à l'échelle mondiale. Basée à Lahti, en Finlande, Kemppi compte plus de 650 professionnels dans 16 pays et a réalisé un chiffre d'affaires de 209 millions d'euros en 2023.

Kemppi – Designed for welders

Copyright © 2024 Kemppi Oy