The Lincoln Electric Company

Frank Armao

Contributing Writer
The Lincoln Electric Company
22801 St. Clair Ave.
Cleveland, OH 44117


Phone: 216-481-8100
fax: 216-486-1751
www.lincolnelectric.com
Contact via email
He is a member of the AWS D1 Committee, chairman of the AWS D1 Aluminum Subcommittee, and vice chairman of the AWS D8G Automotive Aluminum Arc Welding Committee.

Aluminum Workshop: Charpy V-notch testing—Why not aluminum?

December 3, 2014

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Q: In many cases, when I qualify welding procedure specifications (WPS) for steel, I am required to perform testing of Charpy V-notch (CVN) samples, but I’m never required to test Charpy samples for aluminum welding procedures. Why not? A: Charpy V-notch samples are used to determine a...

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Aluminum Workshop: Aluminum-scandium alloys—Strong yet scarce

December 3, 2014

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Q: I’ve seen various references to aluminum-scandium (AlSc) alloys. Apparently, the addition of scandium makes aluminum alloys stronger. But I never see these alloys used in common welded fabrication. Why? Can I weld them? A: The major aluminum companies experimented with Sc additions to a lot...

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Aluminum Workshop: Sizing up feedability and conductivity in contact tips

December 2, 2014

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Q: There seems to be a lot of controversy about what size contact tip to use for GMAW aluminum. Can you give me any advice? A: The contact tip has two functions. First, it provides guidance for the welding wire. Second, it provides a means of conducting welding current from the welding torch...

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Aluminum Workshop: The ABCs of anodizing

December 2, 2014

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Q: What is anodizing? Is it the same as hardcoating, and can I do it myself? Can you weld on anodized parts? A: Anodizing is a process in which a thin, uniform coating of aluminum oxide is formed on the surface of aluminum. Any aluminum alloy can be anodized, but different alloys form anodized...

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Aluminum Workshop: Guidelines for preheating T6

December 1, 2014

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Q: We are welding 6061-T6 that is ¼ in. to 1 in. thick. To weld the thicker materials we are preheating to 300 to 600 degrees F. We are not happy with the strength of the welds. Is there something we can do, such as heat treating after welding, to increase the strength of the weld? A: You can...

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Aluminum Workshop: What determines aluminum filler strength?

December 1, 2014

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Q: I’m confused about various aluminum filler metal strengths. Does the filler designation tell me anything about the strength of the filler or the weld? I looked in AWS A5.10, the specification for aluminum GMAW and GTAW filler metals, and there are no strength requirements even in there. Why?...

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Aluminum Workshop: Weldability of aluminum mold plate

November 26, 2014

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Q: I’m trying to weld some very thick aluminum mold plate. I don’t know what the alloy is. The plate thickness is about 12 in. I’m having lots of cracking problems. Can you tell me what the problem might be? A: In the way of background, most of the molds used for injection or blow molding...

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Aluminum Workshop: Common porosity problems (and how to fix them)

November 26, 2014

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Q: I’m having a lot of problems with porosity in my aluminum welds. Can you tell me what’s causing it? A: As we’ve said before, all porosity in aluminum welds is caused by hydrogen, which is very soluble in molten aluminum but insoluble in solid aluminum. Generally, hydrogen comes from two...

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Aluminum Workshop: Explaining the causes of black smoke

November 25, 2014

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Q: I get a lot of black smoke on the surface of my aluminum welds. What is it, and how can I get rid of it? A: I can tell you what the black smoke isn’t. It is not soot and it doesn’t contain carbon, as most people think. It is, in fact, a mixture of very fine particles of aluminum oxide and...

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Aluminum Workshop: Addressing arc blow

November 25, 2014

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Q: I’m welding aluminum plate and extrusions of various alloys using both GTAW and GMAW. Sometimes I encounter what seems to be arc blow while welding, mostly with GMAW. But since aluminum isn’t magnetic, arc blow shouldn’t be possible. Is it something else? If so, what? A: This is a common...

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Aluminum Workshop: Dissecting a die casting dilemma

November 24, 2014

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Q: I weld a lot of aluminum castings. Most of the time they weld fine, but sometimes the weld blows out at me. What’s going on? A: The problem is caused by the casting process. There are three types of casting processes—sand casting, permanent mold casting, and die casting. The molds for sand...

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Aluminum Workshop: Meet tensile strength requirements with the right filler metal

November 24, 2014

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Q: I am trying to conduct a procedure qualification test on 5083-0 temper material using 5356 filler metal and gas metal arc welding (GMAW). I have welded a number of test plates, but the tensile samples always fail at a tensile strength of 37 to 39 KSI. The code requires a minimum tensile strength...

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Aluminum Workshop: Determining contact tip size

November 21, 2014

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Q: What is the right contact tip size for using 0.0468-in. filler wire to gas metal arc weld aluminum alloys? Some people use a tip that is one size larger (for example, a 0.0625-in. tip on 0.0468-in. wire), while others use the size the manufacturer specifies for 0.0468-in. wire. Still others use...

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Aluminum Workshop: Welding fumes in aluminum MIG

November 21, 2014

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Q: I just started gas metal arc welding (GMAW) aluminum in my shop. I have noticed that a lot of white smoke comes off when I weld. Is this dangerous? Are there other issues with fumes I need to be aware of when welding aluminum? How concerned should I be? A: You are absolutely doing the right...

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Aluminum Workshop: Push/pull guns for aluminum MIG welding—Are they necessary?

November 21, 2014

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Q: I’m just starting to weld aluminum with gas metal arc welding (GMAW). Do I really need a push/pull gun—they’re expensive—or can I use a standard gun with a Teflon® liner and contact tips for aluminum? A: This is not a yes or no answer. It really depends on the type and size of filler...

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