Welding titanium poses unique challenges due to its reactivity at high temperatures. A shielding gas, often argon, is crucial to prevent contamination. TIG (Tungsten Inert Gas) welding is the preferred method for more precision and control. But you can also mig weld Titanium.
Though titanium isn’t as common material as steel, you may weld the metal just by following few proper steps, choosing the right welding wire or electrode and particular shielding gas. The mechanical properties of Titanium makes it highly reactive to elevated temperatures and susceptible to environmental contamination.
If you want to have a good quality weld on titanium base, you need to use proper shielding gas to protect the weld pool from contamination.
How Hard Is it to Weld Titanium?
Fortunately, titanium welding is easy-peasy as it has similarities with nickel alloys and the stainless steel welding process. Following the proper technique of mig welding, you’re allowed to weld titanium, fabricating it in almost every shape possible.
Mig welding involves higher heat and a consumable electrode. Which in turn can lead to challenges such as contamination and porosity in the weld.
So you need to keep the discontinuities in mind and use proper gas shielding to protect the molten weld puddle and reduce weld discontinuities.
Mig Welding Titanium
Despite having similarities with typical steel in terms of steps, titanium has some unique characteristics that make it different from others. For instance, it features lower density, higher melting point, gets contaminated easily, and so on.
In this case, following a specific guideline is crucial for successful welding. Go on to see what you need to perform-
Pre-welding Preparation
Perfectly-welded titanium appears to be a reflective and shiny object. But to achieve that, you must go through each step thoroughly; these are as follows:
a) Clean the Surface
Thoroughly clean the titanium surfaces to be welded. Remove any oxides, contaminants, grime, paint, rusts or oils using a dedicated titanium cleaning solution or a combination of solvents and abrasive materials.
And use a stainless steel brush to get rid of the residuals and suborn dirt on the surface.
b) Clean The Filler Rod & Workspace
The workspace and filler rod must be cleaned up to stay out of a weld failure. Get your hands on sodium hydroxide and a steam cleaner to wipe the contaminations away from the workspace.
After that, utilize an air blower to eliminate moisture. Make sure the tool doesn’t get into contact with any flammable chemical while blowing.
b) Select Right Wire
Choose a filler wire that matches the grade of titanium base metal. The filler wire you use must be capable of holding similar-level properties compared to the titanium’s base.
According to expert welders, the filler metal must decrease yield strength when working with unalloyed titanium. As an alternative, you can choose between the classifications of Ti-6A1-4V and Ti-5A1-2.5Sn to enhance the joint’s flexibility.
When it comes down to Mig welding, using a solid filler metal is ideal. For top-quality titanium welding, the technique involving pulsed current is cost-efficient, especially for a titanium plate of 13mm thickness.
c) Select Right Shielding Gas
Use a high-purity shielding gas, typically pure argon gas, to protect the titanium plates from reacting with atmospheric elements during welding. Ensure that the gas supply is clean and free of impurities. You must choose a trusted supplier while purchasing the shielding gas.
Let’s familiar with the three shielding to get the most out of your titanium welding:
- Primary Shield: It is ideally located at the welding torch, offering the primary coverage needed for the molten weld.
- Secondary Shield: Indeed, a trailing shield tends to offer secondary protection against contaminations. You’ll find it at the welding torch’s end, keeping the heat-affected places safe and secure.
- Backup Shield: You won’t find it pre-adjust into your welding torch just like the primary and secondary. That said, it looks similar to trailing shields, which serve a similar functionality.
d) Select Right Mig Welder
Here is where you need to be smart enough. Chances are your whole struggle will go in vain if you mistakenly choose the wrong welder, even if you collect the correct mig wire and shielding gas.
e) Welding Machine Settings
Ensure that voltage, wire feed speed, and other parameters are appropriate for the specific grade and thickness of titanium. You should use a 200v to 220V Mig welder with 140 Amps input power, for optimal results.
Thus, you’ll find the welder much more powerful and capable of dealing with thicker aluminum plates. DC (direct current) is the only ideal choice to weld through titanium. So make sure you get your hands on the dc-friendly Mig welder.
f) Proper Ventilation
Welding titanium may produce harmful fumes. Work in a well-ventilated area, and consider using exhaust systems to minimize exposure to fumes.
g) Avoid Cross-Contamination
Ensure that there is no cross-contamination from tools or equipment used on other materials. Use dedicated tools for titanium welding to prevent introducing foreign materials.
h) Preheat Considerations
Depending on the specific requirements and thickness of the titanium, preheating the material may be a necessary step to follow. It helps reduce the risk of cracking.
How To Mig Weld Titanium (Step by Step)
Here are the step by step process of mig welding titanium.
- Step-1: Collect Necessary Safety Dresses
While welding, make sure all essential safety gear are ready to use. Wear them and start the main welding. The safety equipments are-
- Gloves
- Leather shoes or boots
- Suitable welding helmet
- A face mask
- Step-2: Gas Cylinder Preparation
As you’ve picked up the pure Argon as a shielding gas, you must prepare the cylinder straight away following the guidance of the manufacturer. Welders must generally meet the correct ratio of shielding gas for best results.
Either choose pure Argon or make the mixture of 25% Argon and 75% Co2.
- Step-3: Current Strength Adjustment
Compared to steels, titanium is less thicker. As a result, it is prone to get damaged if you mistakenly move the heat level up. For 133mm to less thickness titanium, you should reduce the heat.
- Step-4: Begin Titanium Welding
Once you’ve adjusted the current strength and prepared the cylinder, it’s time to start welding. Hold the gun firmly, and don’t rush while joining titanium pieces to parent metal.
After you’ve got your desired size and shape, turn off the welder and go for an observation.
- Step-5: Let the Material Dry
You shouldn’t touch the surface of titanium immediately after the weld. Instead, please wait for a couple of minutes allowing it to get fully relaxed.
Afterward, check for the weld joint to see if everything is okay. If you find any issues, you’ll have to restart the welder to fix them. Thus you may get a successful weld.
Issues in mig welding titanium
Welders may encounter several issues during the MIG welding of titanium, including:
- Oxide Formation: Titanium readily forms oxides when exposed to air at high temperatures. Controlling and preventing oxide formation is crucial to maintain weld purity. Proper shielding gas and cleanliness are essential for acceptable weld.
- Contamination: Titanium is highly sensitive to contamination. Even trace amounts of foreign materials, such as oil, grease, or residue from improper cleaning, can adversely affect the weld quality.
- Porosity: Porosity can occur in titanium welds if shielding gas coverage is insufficient. This can lead to weakened welds and reduced mechanical properties.
- Hot Cracking: Titanium is prone to hot cracking, especially if the material experiences rapid cooling. Proper preheating and controlled cooling measures are essential to mitigate the risk of cracking.
- Heat Input Control: Controlling the heat input is critical due to titanium’s sensitivity to temperature. Excessive heat can lead to material degradation and compromise the mechanical properties of the weld.
- Weld Pool Control: Achieving and maintaining a stable weld pool is challenging with titanium. Proper technique and control are necessary to prevent weld pool irregularities and ensure uniform penetration.
- Weld Discoloration: Titanium is susceptible to discoloration when exposed to high temperatures. Discoloration does not necessarily affect the integrity of the weld, but it can impact the appearance.
- Fume Hazards: Welding titanium may produce harmful fumes, including titanium dioxide. Adequate ventilation and respiratory protection are essential to minimize the risks associated with fume exposure.
- Material Preheating: Depending on the thickness of the titanium and the welding parameters, preheating may be necessary to reduce the risk of hot cracking. Proper preheating practices need to be followed.
Frequently Asked Questions (FAQ’s)
1. Can you mix weld titanium exhaust?
2. What type of welder is used for titanium?
3. Do you weld titanium on A.C or D.C?
4. Which welding type is best for titanium?
5. Can you laser weld titanium?
Some key benefits of laser welding titanium include Precision and Control, Minimal Heat Input, High Welding Speed, Low Distortion & Clean Welds.
6. Can titanium be cold welded?
This oxide layer can interfere with the direct bonding required for cold welding.
Additionally, titanium is a relatively hard and ductile metal, and achieving the necessary plastic deformation at room temperature for cold welding can be challenging.
Last Words
Mig welding titanium doesn’t require you to follow any complicated steps. All you need to do is go through the essential techniques, and you’re good to go.
Alongside the steps, you must pay equal attention to choosing the correct filler wire, shielding gas, and safety gear.
Related Article