Laser hardening

The laser spray process uses a high power carbon dioxide laser focused onto the surface of the part to be metallized. A carrier gas such as belium blows metal particles into the path of the laser and onto the part. The laser melted particles may fuse to the surface, or may be incorporated into an aHoy in a molten surface up to 1-mm thick. The laser can be used for selective aHoying of the surface, for production of amorphous coatings, or for laser hardening. 

The more important metallic coating methods such as electroplating, spraying, hot-dipping and diffusion have already been considered. There are, however, several other methods which have certain advantageous features and therefore find exclusive application in specific fields. These include new techniques such as laser hardening and alloying. ... 

Laser Hardening and Modification. Lasers are used to surface harden ductile steels and improve the toughness to a depth of 0.35 min or more. Lasers can also be used to bond solid or powder coatings to a surface. Typical coalings are nickel or titanium carbide on iron, and nickel, cobalt, manganese, and titanium carbide. TiC. on aluminum. I1 sc of lasers with other specialized coating methods is common. 

Surface hardenability - laser hardening, flame hardening or inductive hardening,... 

FIGURE 4.93 Typical hardness profile in the surface layer after laser hardening... 

Thermal (Flame/Induction/Electron Beam Hardening and Melting/Laser Hardening and melting)... 

Beam Steering, Routing, and Optical Switching and Laser Hardened Optics... 

Although most optical elements involve low level light, liquid crystals are actually excellent laser-hardened materials capable of handling very intense pulsed lasers or high power continuous wave cw lasers. These studies have shown that common liquid crystals such as 5CB and E7 can withstand a nanosecond laser pulse of 10 J/cm (corresponding to an intensity 10 W/cm ), thus making them particularly useful to construct high power laser optics such as polarization rotators, wave plates, optical... 

Fig. 4. Hardness—depth curve for case hardening of 0.6 wt % C steel by laser heating (7).

Although the element is a metalloid, the long, brittle, crystals have a metallic shine. The white, tasteless oxide (arsenic trioxide As203) has been famous and notorious ("inheritance powder") even after centuries traces can be found in bodies. The arsenic compound "Salvarsan" was first used by Paul Ehrlich for the treatment of syphilis — the start of chemotherapy. Popular today as a semiconducting material. Component of LEDs (light-emitting diodes) and lasers. Arsenic hardens lead, used earlier in letter-press printing, today only for lead shot. 

Laser heating, case hardening by, 16 200 Laser heterodyne radiometry, 23 142 Laser-induced breakdown spectroscopy (LIBS), archaeological materials, 5 743 Laser-induced EDC cracking, 25 646 Laser-induced fluorescence, 23 127 Laser-induced fluorescence imaging, application in combinatorial chemistry, 7 404... 

Multiplexed diode laser sensors have also been applied for measurements of gas temperature, velocity, and H2O partial pressures in hypervelocity air flows at the Calspan University of Buffalo Research Center s (CUBRC) Large Energy National Shock Tunnel (LENS Tunnel) in Buffalo, New York [12]. The sensors were developed to provide quantitative characterization of the facility operation and, in particular, the freestream flow properties as a function of time. The measurements were recorded using a hardened probe, which contained critical optical components and photodetectors, that was installed directly into the hypersonic shock-tunnel near the nozzle exit to minimize complications due to boundary layers and facility vibration. 

The automotive industry, which turned to laser transformation hardening of engine and other drive train components, is now seriously investigating the solar hardening process,... 

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