Laser Welding of Brass

Metallurgical Considerations: Some metals cannot be laser welded due to their metallurgical
composition. Brass, for example cannot be laser welded. Why? Brass is an alloy of copper and
zinc. The problem with brass is that the melting temperature of the copper (1084C) exceeds the
boiling (vaporization) point of the zinc (907C). Zinc melts at 419C. By the time the copper melts
the zinc has vaporized. When the zinc vaporizes it explodes and splatters metal over a large
area. The same is true with bronze and phosphor bronze

Interesting answer, based on your assumptions it would be impossible to produce the alloy brass, as all the zinc would vapourise in the furnace. I have succesfully had samples produced, with stranded copper wire laser weded to brass contact tags.

This used a pulsed Yag machine designed for jewelery welding. the machine has binoculars and the operator holds the parts to be welded under the aiming spot and operates the laser by foot switch.

Pulsed welding is the way to go, it avoids sustained temperatures on the zinc. I would expect the making of bulk alloys would proceed by adding the higher boiling metal to a vat of the melted - dropping copper lumps into stirred molten zinc for example, so they dissolve to the desired alloy point. A molten surface flux might also be used.

Aurizon is correct. However, there are some things you can do to increase your odds.1) use longer pulses. Greater than 5 ms is recommended to obtain penetration and reduce the temperature gradient. 2) de-focus slightly to improve beam homogeneity. 3) A gas jet can be used to prevent vaporized zinc from condensing on the objective lens. Good ventilation is required.