Feasibility Study of Direct Infrared Pulsed-Laser Marking of Alphanumeric and QR Codes on Flat Copper and Brass Alloy Specimens as Material Surrogates for Ammunition Traceability Applications

Background and Objective: Laser marking has emerged as a promising technique for producing controlled surface modifications on metallic substrates. This preliminary material-level feasibility study investigates the Infrared (IR) direct pulsed-laser marking (DP-LM) of flat copper and brass (CuZn37) surrogate specimens for potential ammunition-related marking applications. Methods: Alphanumeric and quick-response code markings were produced using selected laser-processing conditions and evaluated in terms of subjective visual clarity, surface roughness, readability and functional scannability. The investigation was limited only to the flat surfaced copper and brass substrates, while excluding the aging effects, curve surfaced ammunition components, mechanical loading, deformation, abrasion, or handling conditions arising from firearm feeding, chambering, firing, and extraction mechanisms. Results: The findings demonstrate that enhanced direct laser marking conditions maintained the controlled surface roughness profile and produced visually distinguishable and functionally scannable markings on the studied material. These findings provide preliminary material-level proof that IR DP-LM justifies further investigations. Conclusions: Motivated by the need for optimized identifiers for law enforcement organizations, future investigations on actual cartridge cases and under representative service conditions together with standardized verification procedures are required before operational conclusion can be drawn.