Features of laser radiation interaction with metals having cryogenic temperature

✍ Scribed by Tatiana Khatko; Viacheslav Khatko

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 972 KB
• Volume: 254
• Category: Article
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2007.08.061

✦ Synopsis

In this paper we determine the features of the thermophysical processes involved in the interaction of laser radiation with metals that have cryogenic temperature. To do so, we use a one-dimensional model that involves heating a semi-infinite solid by a point thermal source with a constant flux density. Temperature fields, heating and cooling rates in the laser-irradiated zone for iron and titanium at the ambient temperatures of 77 (liquid nitrogen), 293 and 573 K were calculated. The intensity of the laser irradiation enabled the melting temperatures of 1933 K and 1812 K on the Ti and Fe surface, respectively, to be reached. The duration of the laser pulse was 4.5 ms. We show that a drop in ambient temperature from 573 to 77 K leads to a rise in cooling rate from 3.25 Â 10 3 and 6.4 Â 10 6 K/s to 4.25 Â 10 3 and 1.3 Â 10 7 K/s in the Ti and Fe targets, respectively. Agreement was good between the calculated depths of melting and phase transformation isotherms and the experimental depths of the interfaces of melting and heat-affected zones.