How do I Go About Welding Titanium?
Welding titanium is not rocket science, as most people tend to see it. Due to some subtle differences, however, a trained eye or knowledge of a few of the basics could be the difference between pass and fail. The basic steps for titanium welding are quite similar to welding other metals, and only require different amounts of focus. Whereas welding steel might be 30% preparation and 70% actual welding, titanium welding is essentially just the opposite: 70% preparation and 30% welding time.
When it comes right down to the actual process of "running the bead," as they say in the trade, welding titanium differs little from the welding of any other ferrous metal such as steel or stainless steel. As long as some key elements are controlled, welding titanium can be done by almost any experienced welder.
Some of the most important steps take place before and after the actual welding occurs. Eliminating the impurities on the material is first and foremost. Clean material is absolutely crucial to the overall integrity of the titanium weld. This can be achieved through chemical cleaning. Even microscopic bits left behind from a grinding disk, or the oxidized surface itself must be removed. The natural oils on the skin can even contaminate the filler rod. All of these surfaces must be as clean as possible.
Once all of the surface impurities are eliminated, the next factor to consider is the atmosphere, since the actual air around the titanium weld can cause problems. There are several ways to overcome this dilemma. Specialized equipment is available for welding titanium, depending on the available budget. Trailing cups can work for short jobs; however, for production, a small investment of a vacuum-controlled chamber might be in order.
Yes, a chamber is as expensive as it sounds, but it is a worthwhile consideration. The reason: while welding titanium, heat naturally spreads into the surrounding material. This is known as the heat affected zone or HAZ. Oxygen can and will react to titanium at temperatures just below its melting point, and therefore cannot come into contact with the HAZ while it is still above a certain temperature. The entire area of the HAZ must be constantly purged with pure argon until the surface temperature no longer reacts to the oxygen in the atmosphere.
Controlling these key variables is essential to successfully welding titanium. It is important to note that welding titanium is considered a very expensive process; therefore, it is not recommended for anyone who may still be learning the art of welding.
Welding titanium is considered expensive, but titanium itself is very expensive compared with other metals, so even if you can afford the set up, you'll still be shelling out quite a bit of money for the raw material.
This is why titanium is usually used in alloys, so it can augment other metals, like aluminum and iron.
I have a friend who competes in cycling races and she has a titanium frame on her bike. Extremely expensive, but durable and light.
I guess it was made by this kind of welding, so no wonder it is so expensive.
I had no idea that it took so much forward planning and effort to weld titanium compared with other metals.
I guess it always gets thrown around as being particularly strong, but I hadn't thought about that in terms of how strong the joins would have to be.
It makes sense though. If you have a material that is extremely strong, if it is put under pressure (and why use such a strong material if it isn't going to be put under pressure?) the welds would be the weakest point.
So when you were using that welding torch, you'd have to make sure that it was the absolutely best join you could make it, or you might as well use a weaker metal.
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