UID Marks on Anodized Aluminum

UID (Unique IDentification) applications are becoming increasing familiar to Department of Defense (DoD) suppliers since the DoD now mandates the ability to track product history throughout the supply-chain.

Unique identifiers are created by first selecting one of three “languages” or Format Identifiers, which describe the format of the data descriptors used in the UID string.

After choosing a format, the manufacturer’s identification along with product part/serial identification numbers are combined with predefined formatting and transmission characters. The UID string is then sent to the part marking system, in this case to our WinMark Pro laser marking software, where the data is encoded into a Data Matrix™ ECC200 symbol for direct marking onto the part or tag.

Laser welding is typically performed without adding filler material to the weld. This creates a homogenous junction between the two pieces without introducing foreign material in the form of filler alloys. The downside is that part fit up at the weld interface must ideally be zero to prevent undercutting of the weld joint. In actual practice, a slight gap not exceeding 10% of the thinnest piece or the actual weld depth, whichever is less, is acceptable. In addition, the conventional welding technique of creating initial spot welds at intervals along the joint helps to prevent material separation during the actual weld pass.

In this application, we fillet welded a 0.15 mm (0.006”) thin steel cover to a much thicker steel substrate. Our beam delivery setup consisted of a 63.5 mm (2.5”) positive meniscus lens, which provides a 100-micron (0.004”) spot size with a 1.8 mm (0.07”) depth of focus. An argon shield gas was adjusted to flow over the processing area at a rate of 3.9 cubic feet per minute (CFM) to prevent the molten weld pool from reacting with the surrounding atmosphere. Each weld was completed in approximately 1.3 seconds using 200 watts of power at a velocity of 15 inches per minute.