Unformatted text preview: 2 /s, C = 0.50 J/gK, k = 0.4 W/cmK, T m = 1809 o K, L f = 13.8 kJ/mol, L v = 350 kJ/mol, T v = 3135 o K, R=60% 3 Mild steel is to be welded with a multi-kilowatt CO 2 laser. Using the model of Swift-Hook and Gick, estimate the power required to produce a weld of 2 mm width and 4.5 mm depth at 1 m/min. α = 0.09 cm 2 /s, k = 0.4 W/cmK, T m = 1809 o K 4 Holes are to be drilled in 0.5 mm thick nickel with a diameter of 0.13 mm, using a pulsed Nd:YAG laser with a 4 kW peak power output. Use energy balance equations to estimate the energy needed and the pulse length, assuming a nearly square pulse in time. Show that the time to reach vaporization at the surface is very small, based on the results of the uniform irradiance model. ρ = 8.9 g/cm 3 , C = 0.44 J/gK, k = 0.91 W/cmK, T m = 1726 o K, L f = 298 J/g, L v = 6303J/g, T v = 3187 o K, R=60%...
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- Spring '10
- Carbon steel, A36 steel, Red-short, uniform irradiance model