Category: Research & Development

Electrons are Cheaper than Photons (by the watt)

plasma welding overlay

My first job was in the Hughes welding research lab and I loved it. But my lab experience started as a youngster going to my mom’s radiation mutation genetics lab at UT Austin. My job was pipetting mutated drosophila (moving fruit flies from one test tube to another by sucking them up in a straw). Laboratories are in my blood.

We built our lab at ARC Specialties years ago so we could determine project feasibility and optimize process parameters BEFORE we build a machine.

In our lab, we have answered questions such as can you weld MoRe? Pure Tungsten? Make bullet-resistant coatings on Ti? Clad pipe 40′ deep? Use ESW for additive? Create wear-resistant coatings for aluminum? Maintain bond line flatness +/- .005′”? Too much fun!

This week’s challenge was to make .02″ thick metal to metal wear-resistant coatings for mud motor transmissions with a metallurgical bond, minimal cracking, and useable in the as-welded condition without a laser. With a little help from our friend Jean-Marc Tetevuide we succeeded.

If you have a manufacturing problem you would like for the ARC team to investigate contact me. If it is interesting we won’t even charge you!

At ARC Specialties we thrive on problems, send us yours!

– Dan Allford

Be Narrow Minded

 

I’m a long time advocate of narrow gap welding. The advantages are tremendous, but the challenges are too. A 5″ thick standard V Butt weld with a 75 degree included angle has five times the weld volume of a 1″ wide 5″ Square Butt. This means a narrow gap joint would have five times less weld wire, five times less arc time, much less distortion. And fewer defects because every inch of weld that you don’t make is an inch you don’t have to inspect and possibly repair.

Why isn’t narrow gap the standard technique for welding heavy sections? Because the technical challenges of welding vertical walls in confined spaces are huge. For good sidewall fusion, the arc must impinge on the walls. Otherwise, you risk lack of fusion defects at the bond line. Our new Narrow Gap Hot Wire Torch features a servo tungsten electrode oscillator to point directly at the sidewall. That is only half the battle. The wire must follow the tungsten. We did just that using a second independent servo this allows us full control of arc and the filler wire position. Finally, we use our HOT ONE AC constant voltage hotwire system to double the deposition rate, which cuts weld time in half.

To see a video including Xiris Automation Inc. arc monitoring click: https://lnkd.in/eBTHYgh

Fatigue Life of Additive Manufactured Aluminum

Thanks for the comments & questions regarding Additive Manufacturing (AM) and material properties. Our motto, see below, really is our mission statement. We learn when you send us problems.

Today we post a video reporting on material properties of AM build aluminum parts. To maximize the material properties of aluminum requires alloying and heat treatment. Typical aluminum welding wires are either silicon alloy 4000 series or magnesium alloy 5000 series, neither of which is heat treatable. Brian Harrison with Alcotec Wire Co graciously supplied a spool of heat treatable copper alloyed 2319 wire. After solution heat treat and aging, we measured tensile strength at 63,000 psi. This means you can use AM to build an aluminum part with the strength of steel and 1/3 the weight.

Next, we built a 5356 aluminum test specimen using AM for fully reversed cyclical fatigue testing at 70% of the tensile strength (130% of yield). The part survived 5,500 cycles. Less than a heat-treated 6061-T6 part but not bad. This is useful data as we build our reference library of AM material properties.

At ARC Specialties we thrive on problems, send us yours!