Small-lot, precision electrical contact-containing devices frequently require manual adjustment of their contact gaps under a microscope; a time consuming, skilled operator-dependent procedure. Laser forming has been shown effective in bending ∼mm-thick, low strength, flat steel alloy stock and is evaluated herein as a high productivity, high precision alternative. The application discussed uses thin, high reflectivity, high conductivity, and high strength Neyoro-G™. Since laser forming requires thermal-gradient-induced non-homogeneous plastic strain, size-scale and material properties were of concern. Calculations employing simple models from the literature and a non-linear, transient finite element analysis (FEA) were used to evaluate feasibility and suggest laser processing parameters. The FEA model employed temperature-dependent mechanical properties; modeled both a scanned-spot and stationary bar-shaped source equal to the contact width; and used heat inputs chosen to promote through-thickness thermal gradients with peak temperatures at the Neyoro-G™ final heat treatment temperature (to avoid softening). Material properties, process parameters and initial and final material conditions are discussed and related to bi-directional bending behaviour. The bar-shaped heat source was found to be more effective both by modelling and in reality.
Precision adjustment of spring contacts using laser forming
D. O. MacCallum, G. A. Knorovsky, J. A. Palmer, J. D. Arvizu; March 23–25, 2010. "Precision adjustment of spring contacts using laser forming." Proceedings of the Pacific International Conference on Applications of Lasers and Optics. ICALEO® 2006: 25th International Congress on Laser Materials Processing and Laser Microfabrication. Wuhan, People’s Republic of China. (pp. P507). ASME. https://doi.org/10.2351/1.5060922
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