ABSTRACT
Laser .................................................... 496 11.1.6 Nd-YAG Lasers............................................ 499 11.1.7 Ruby Lasers................................................. 501 11.1.8 Longitudinal Modes of Laser Beam .......... 502 11.1.9 Focusing Properties of Lasers .................... 504 11.1.10 Collimation .................................................. 507 11.1.11 Coherence .................................................... 508 11.1.12 Depth of Focus............................................. 508 11.1.13 Transverse Modes in Lasers ...................... 514 11.1.14 Temporal Characteristics of Lasers........... 515 11.1.15 Q Switching of the Laser Beam................. 517
11.1.16 Application of Lasers for Material Processing .................................................... 520
11.1.17 Laser-Material Interaction ......................... 523 11.1.18 Reflectivity and Absorptivity...................... 526 11.1.19 Laser Penetration ....................................... 529 11.1.20 The Temperature Field............................... 531
11.2 Electron Beam Heating............................................. 533 11.2.1 Introduction................................................... 533 11.2.2 Generation of Electron Beam....................... 534 11.2.3 Characteristics of EB.................................... 537 11.2.4 EB — Noteworthy Points .............................. 538 11.2.5 EB — Material Interaction ........................... 539 11.2.6 Commercial EB Equipment ......................... 541
In the last chapter we have discussed heating by electromagnetic radiation which ‘‘induces” heat in the object. In the last two decades two heat sources were developed which create heat in the object on incidence by focusing. The first such source is ‘‘laser” which is essentially a light beam which may or may not be in the visible range.
