Shielding – Do you have gas? Do you need it?

This blog is going to be slightly different from the others.  We’re going to talk about a weld process variable as the primary consideration and work backwards into effects on the work piece.  Rather than what directly affects you, I’d like to talk about what challenges us, the welders.

Today’s topic is shield gas.

What is it?  It is an integral part of most atmospheric weld processes (laser welding, TIG, MIG, plasma arc).  It is used to displace the reactive gasses found in the air we breathe.  Oxygen, nitrogen, and carbon dioxide, to name a few.

Why does it matter?  If the welded material is reactive with those gasses, it can be quite catastrophic to the quality of the part.  Our cars and kitchen appliances are painted for the same reasons.  Nobody wants a car or can opener that rusts when just sitting around.  Likewise, nobody wants a weld that is mostly oxidized (rusted) metal.

When does it matter?  Good question.  Thanks for asking.  It doesn’t always matter.  Some metals are somewhat self-shielding or not readily prone to reacting with air.  These metals don’t demand protection.  Gold is quite resistant to oxidation.  Stainless steel, while not immune, does have characteristics that allow for welding without an inert environment under certain circumstances.  Titanium is VERY sensitive to environment and extra precautions need to be considered when welding this touchy metal.  (Titanium does weld quite nicely otherwise.)

What kind of gasses are used? Another good question.  The most common industrial gas is argon, since it is very stable and virtually non-reactive even at elevated temperatures.  It is typically distilled from the atmosphere.  Helium is also used frequently.  Nitrogen is effective for use on certain metals.  Even carbon dioxide, which can be reactive, is a good candidate under certain circumstances.  In theory, any of the noble gasses ought to be effective at displacing reactive gasses.  In reality, you won’t find too many welding houses running to their local neon supplier for shielding gas, though.

Why does this matter to me? Ah, now to the selfish heart of the matter.  The simple answer: Money.  Gas costs money to purchase, to store, to control, and to deliver to the work piece.  Also, a cubic foot of helium is much more expensive than a cubic foot of nitrogen, which in turn is much more expensive than using no gas at all.  If you have a high-volume welding job, choosing the right gas or no gas can have a notable effect on your part price.

How do I know which gas to choose?  Contact and expert at 860.653-0111. They will have the experience required to help you decide which gas is right for your project.

Heat sinks for welding: keep your cool

“I can’t possibly assemble this product with a weld.  It’s too sensitive to heat.”

Really???  Tell me more.  This is probably not the problem you think it is.

Yes, welding involves heat.  After all, we’re talking about melting the stuff your part is made of, and unless that stuff is made by Velveeta, that melting point is probably quite high – several thousand degrees.

How on earth can you possibly prevent that much heat from getting inside a delicate electronic housing?  Well, the answer is pretty simple, believe it or not.  Send that heat somewhere else. 

How do we do that?  The same way your internal combustion engine, computer CPU, and home heating systems do – with an efficient heat transfer medium, a.k.a heat sink. 

A heat sink can be as simple as a copper block which sits adjacent to the weld, or as complex as a liquid cooled, thermally regulated conformal attachment with thermal paste to ensure maximum thermal transfer.

We don’t need to discuss design specifics here, since that’s not the point.  What needs to be drilled home is that so long as it’s possible to draw the heat out of the part faster than it can transfer to the temperature-sensitive components near the weld, you can indeed incorporate a weld into your part. 

Here’s that pesky disclaimer – contact us at 860.653-0111 to talk about the details for your heat sensitive project.  They will give you part specific guidelines and help you keep your cool when the heat is on. 

We’re playing music with lasers for the 4th of July

It’s almost the Fourth of July, and before we all head out to celebrate with fireworks and barbecues, I thought we’d do something a little different to kick off our first video blog.  What’s the perfect song for Independence Day?  The “Star Spangled Banner” would be a pretty good choice, right?  Well, how about the “Star Spangled Banner” played by a high power industrial laser! Check out the video below:

This is something I’ve been wanting to do for years, and it combines two interests of mine – music and lasers.  How was this accomplished?  Well, very briefly, the frequencies of the notes in the “Star Spangled Banner” fall within the frequency range of the laser.  I programmed the machine to fire the laser at the right frequencies to match the notes in the song, and matched the beam on time to the length of each note (imperfectly).

So, enjoy the music and “fireworks” from the sparks flying off the titanium and two alloys of aluminum.  Feel free to leave comments or questions in the comment section.  I think this was so cool we’ll have to do it again.  Happy 4th of July!