Best Tungsten For Welding Aluminum

Best Tungsten For Welding Aluminum - Tungsten is an uncommon metal element used in the production of gas tungsten Arc welding (GTAW) electrodes.

The GTAW process is based on the hardness of tungsten and its high-temperature resistance to transmit this welding power to an arc.

Tungsten is the most melting temperature of any metal, at 3,410 degrees Celsius.

These non-consumable electrodes come in a range of lengths and sizes.

Best Tungsten For Welding Aluminum

They comprise either pure tungsten, or an alloy of tungsten, rare earth metals and oxides.

The choice of one for GTAW is dependent on the type of base material and thickness as well as whether you are welding with an alternating (AC) or direct (AC) and directly current (DC).

The three different options for the end of your preparation either balled, pointed or truncated can be crucial to optimize the outcomes and keeping out contamination and Rework.

Each electrode is color coded to ensure that there is no confusion about the type of electrode.

The color appears on the end of an electrode.

Pure Tungsten (Color Code: Green)

Pure electrodes of tungsten (AWS class EWP) comprise 99.50 percent tungsten.

They have the highest consumption of all electrodes.

They typically , they are less expensive than alloyed electrodes.

Best Tungsten For Welding Aluminum

They form a clear balled tip after heating and offer excellent stability of the arc for AC welding that uses the balanced wave.

Pure tungsten provides excellent stability of the arc for AC sinewave welding particularly on magnesium and aluminum.

It isn't typically employed for DC welding since it isn't able to offer the strong arc start of ceriated or thoriated electrodes.

Thoriated (Color Code: Red)

Thoriated electrodes made of tungsten (AWS class EWTh-2) comprise the minimum of 97.30 percent of tungsten and 1.70 up to 2.20 percent thorium.

They're known as two percent thoriated.

They are the most frequently employed electrodes and are highly regarded for their long-lasting durability and convenience of usage.

Thorium improves the properties of electron emission of an electrode.

It increases the speed of arc start-up and allows for greater capacity to carry current.

This electrode functions well beneath its melting point, this results in a lower consumption rate and prevents arc drift for more stability.

Best Tungsten For Welding Aluminum

As compared to other electrodes, these electrodes are less likely to deposit tungsten in the weld puddle which results in less contamination of the weld.

These electrodes are used mostly to perform specialty AC welding (such as thin-gauge aluminum or materials less than 0.060 inches) or DC welding, whether the straight or negative electrodes on stainless steel, carbon steel, nickel, or titanium.

When manufacturing, thorium is evenly distributed across the electrode.

This allows the tungsten to maintain its sharp edge, which is the ideal shape for welding thin steel after grinding.

Be aware that Thorium is radioactive.

Therefore it is essential to follow the instructions, warnings and guidelines of the manufacturer as well as the Material Safety Data Sheet (MSDS) to use it.

Ceriated (Color Code: Orange)

Ceriated electrodes of tungsten (AWS class EWCe-2) comprise the minimum of 97.30 percent of tungsten as well as 1.80 up to 2.20 percent cerium.

They are often referred to as 2 percent cerium-ceriated.

They are most effective in DC welding with low current levels, but can also be utilized effectively when used in AC processes.

Best Tungsten For Welding Aluminum

Because of its excellent arc start with low amps, ceriated is now widely used in applications as pipe and orbital tube fabrication and thin sheet metal work as well as jobs that involve tiny and delicate components.

Similar to thorium, it's most effective in welding stainless steel, carbon steel, nickel alloys and titanium.

In certain cases, it is able to be used to replace 2 percent of the thoriated electrodes.

Ceriated tungsten may have slightly different electrical properties than thorium however, most welders are unable to tell the difference.

Ceriated electrodes that are used at higher amperages isn't advised due to the fact that higher amperages cause oxides to move quickly towards the heat source at the point, which removes the oxide content and negating the process's advantages.

Lanthanated (Color Code: Gold)

Lanthanated electrodes of tungsten (AWS class EWLa-1.5) have at least 97.80 percent of tungsten, in addition to 1.30 percentage of 1.30 percent to 1.70 percent lanthanum, also known as the lanthana.

They are referred to as 1.5 percent of lanthanated.

They have excellent beginning of arc, and a low permeability, and a burnoff rate, good arc stability, and excellent reignition characteristics--many of the same advantages as ceriated electrodes.

Lanthanated electrodes also have the characteristics of conductivity that are found in 2 percent Thoriated the tungsten.

In certain situations, 1.5 percent lanthanated can substitute 2 percent thoriated without needing to make major welding program modifications.

Best Tungsten For Welding Aluminum

Lanthanated tungsten is a great choice for those who want to maximize your welding abilities.

They are ideal for welding with AC or DC electrodes, with a negative pointed end, or are balled using AC Sine wave sources of power.

Lanthanated tungsten keeps a sharp point, which makes it a great choice for welding stainless steel and steel DC or AC using square wave sources of power.

Contrary to thoriated, tungsten electrodes can be used for AC welding.

They, just like Ceriated electrodes, permit the arc to be initiated and sustained even at low voltages.

In comparison to pure tungsten an addition of 1.5 percent lanthana boosts the capacity of carrying current by about 50 percent depending on the electrode size.

Zirconiated (Color Code: Brown)

Zirconiated electrodes of tungsten (AWS designation EWZr-1) comprise the minimum of 99.10 percent of tungsten and 0.15 or 0.40 per cent zirconium.

A zirconiated tungsten electrode produces an extremely stable arc and resists tungsten spitting.

Best Tungsten For Welding Aluminum

It is perfect for AC welding as it maintains an elongated tip and an excellent protection against contamination.

Its capacity for carrying current is equal to or more than that of thoriated-tungsten.

Zirconium is not is recommended as a material for DC welding.

Rare Earth (Color Code: Gray)

Rare-earth electrodes made of tungsten (AWS classification : EWG) include unspecified additives made of rare-earth oxides, or hybrids of various oxides, however manufacturers are required to specify the percentage of each additive within the product.

Best Tungsten For Welding Aluminum

Based on the additives used that are used, the desired outcomes can be an arc that is stable in both AC or DC methods, longer lasting than thoriated or tungsten, the capability to use an electrode with a smaller diameter to accomplish the same task as well as the ability to use a larger voltage for the same electrode and significantly less spewing.

Tungsten Preparation - Balled, Pointed, or Truncated?

After deciding on a type of electrode The next step is to choose the appropriate end-preparation.

The three options are pointed, balled and the truncated.

Common current ranges for electrons using shielding argon.

Balled tips are typically employed on pure tungsten and zirconiated electrodes.

It's recommended to use in conjunction in conjunction with the AC procedure for sine wave and traditional quad wave machines.

To make sure that you ball the tip of the tungsten correctly you just need to use the AC amperage that is recommended for the diameter of the electrode and you will see a ball form at the electrode's edge.

In the case of the end that is balled must not exceed 1.5 times the size of the electrode (for instance, a 1/8-in. electrode should have the shape of a 3/16-in.-diameter ending).

A larger sphere near the tip of the electrode may cause arc instability to decrease.

It can also fall off and pollute the weld.

A pointed or truncated edge (for pure tungsten, ceriated, and lanthanated and thoriated varieties) should be used in Inverter AC or DC welding procedures.

To properly grind the tungsten make use of a wheel specially designed for tungsten grinding (to keep contamination out) and one composed from Borazon as well as diamond (to keep tungsten's brittleness at bay).

Take note that if you're grinding thoriated tungsten, be sure you keep track of and capture dust, and have adequate ventilation at the place of grinding and adhere to the instructions and warnings of the manufacturer and MSDS.

Make sure to grind the tungsten straight onto the wheel instead of at 90 degrees to ensure that the marks on the grind are along the distance of the electrode.

By doing this, you reduce the appearance of tungsten ridges which could cause an arc that wanders as well as melt down into the puddle, leading to contamination.

In general, you'll need grinding the surface of the tungsten until it is not greater that 2.5 times the electrode's diameter (for instance, to make 1/8-in. electrode, you would need to grind the surface from 1/4 to 5/16 inches. long).

grinding the tungsten until an arc-like shape eases the transition to arc start and produces a better focused the arc to improve welding performance.

When welding very low currents on thin materials (from 0.005 or 0.040 in. ) it is advised to grind the tungsten until it reaches the point.

A pointed tip permits the welding current to move to a centered arc, and prevents thin metals, like aluminum from bending.

The use of tungsten pointed for higher-current applications is not recommended since the greater current could cause the tip to be blown away from the tungsten, causing contamination of the weld puddle.

In the case of higher-current applications it is recommended to use a truncated tip.

To get this shape grind the tungsten into an elongated taper as previously described before grinding to a 0.010up to 0.030in. flat area on the other side of the tungsten.

This flat land prevents the tungsten from moving to the other side of the arc.

Also, it prevents the formation of a ball.

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