Laser Welding Two Rings Together

Any idea why it is hard to fill a void when soldering two rings together at the top & bottom? It is like the metal has a memory & no matter how many times I hit it with the laser, there remains a small line or crack. I can add more gold, but the line continues to appear. It almost makes it easier to torch solder the rings together. There has to be a metallurgic reason for this to happen.

Hi,

interestingā€¦so, the metal from each ring is not pooling and melding in between? so, the metal is melting but being pulled back onto each ring by surface tension?

perhaps adjust energy? angle of attack?

may i ask?ā€¦what is the metal?

julie

It sounds likke the rings might be white gold or Sterling, both, either of which can easily have this problem?
When soldering rings together, I tend to only use the laser to lightly tack the rings together, and then pull solder through the assembly with a torch.

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Hi,

i dont have a laser, but with my welder i am learning that angle of attack affects the direction the melt goesā€¦i just learned that i can make contact with the side of the electrode to push metal downā€¦

ie: lets say i have a piece of wire laying on a flat piece of sheetā€¦instead of of pointing the electrode at a 45 degree angle into the seam area, between the two, i point it straight down/ perpendicular toward the sheet (effectively a 90 degree angle to the sheet)ā€¦and instead of touching the blunted tip to the metal (sterling in this example) i instead touch the side of the electrode blunt point to the wireā€¦and the metal flows down into the seam area nicely

i think the side emits less powerā€¦to the thinner wireā€¦and a stronger power goes off the tip to the sheetā€¦

big improvement in doing fills etc

julie

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great questionā€¦with many potentially different answersā€¦ torch soldering might be the better solution. the two rings will have a memory, unless annealed first. laser welding would not heat the entire rings enough to relax that memory, by annealing, while as torch soldering wouldā€¦if you have to bother with annealing the rings first, why bother with laser welding when torch soldering would do the same thing simultaneously. .if the contact point between two circular rings are very thin, just an edge, laser welds would tack them together but with insufficient amount of material to hold them together and resist them from springing apart. adding more gold should help but it would have to be more than you would want to useā€¦and there will still be tension in the ringsā€¦anything that has a circular geometry will have that tension memory locked inā€¦ the arc welding solution proposed by W would work with thin wires and thin sheetā€¦ arcs are more diffuse than lasersā€¦but if the rings that you are trying to weld together are thick pieces of metal, more than 14 or 12 gauge wire, there still wonā€™t be enough total heat energy to anneal them and relax the springinessā€¦This could just be one aspect of the problem and I also could be entirely wrong on this, so further comments would be most welcome and appreciated. Iā€™ve done all fabrication and decorated ring shanks with leaves, wires, etc and have run into the same problems with things not wanting to stick, even with torch soldering. Iā€™m also a hobbyist and not a professional.

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the angle of attack is critical and you are so right about thatā€¦ itā€™s something learned by trial and error.

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Hi!

ah! tension! interesting!
i wasnt sure i understood what was happening to the OPā€¦but mow that you mention tension, i think i understand now.

and its funny, because when i practice/ test weld rings, i can ā€œfeelā€ tension building upā€¦a ā€œdistortionā€ā€¦i have this weird feeling about it!ā€¦i just discussed it with orion supportā€¦and now that you mention it, maybe the ā€œsenseā€ is real!

julie

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i think so tooā€¦ annealing first will relax the metalā€¦so you could try that as an experimentā€¦ annealing two separate rings however might lead to them not being exactly with the same roundnessā€¦ itā€™s intrinsic to circular geometry, especially ovals, or anything eccentricā€¦

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It could be a shrinkage crack when the weld pool cools from the 3000 or so degrees down almost instantly to the ambient temp. The metal shrinks and tries to draw the rings tighter together. If the rings are already tight, the weld will crack as it passes through the ā€˜hot shortā€™ phase of cooling down. This happens with my pulse arc welder. Preheating the items to about 100 degrees often helps as it slows down the cooling of the weld pool, and the amount of shrinkage is less in comparison the pieces being joined.

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