An overview of research in the fields of laser surface modification and laser machining at the Integrated Manufacturing Technologies Institute, NRC

Abstract

At the Integrated Manufacturing Technologies Institute (IMTI), National Research Council Canada, research in laser material processing has been underway for more than a decade. Topics being investigated include the development of laser welding, cutting, and drilling applications, surface modification techniques, laser depth controlled machining, stereolithography (SLA), and selective laser sintering (SLS). This paper reviews the activities in laser surface modification and laser depth controlled machining of ceramics.

Effect of Inhomogeneity on the Stress in Pipes

“…where the constants A and B are found using equation (7). The mathematical properties of the Kummer's functions are tabulated in standard texts.…”

“…The application of Functionally Graded Material (FGM) in various engineering components has become widespread in recent decades, and consequently this area has received considerable scientific attention [1][2][3][4][5][6][7][8]. The physical properties of the FGM are engineered in such a way that for a specific application they have optimal spatial variation.…”

“…Here the stresses in pipes are considered where the elastic properties vary in the radial direction but are constant along the length. This type of inhomogeneity can be due to several causes: directional cooling leading to a microstructural gradient [3]; phase segregation arising as a result of centrifugal casting [2]; property degradation of the fuel cladding in nuclear reactors [9]; chemical and vapor deposition [8]; and surface modification using laser technology [6,7].…”

Bending of inhomogeneous curved bars

“…Of particular interest in this contribution is the special case where the elastic properties within a circular plane bar vary in the radial direction but are constant across the depth. This type of inhomogeneity can be due to several causes: directional cooling leading to a microstructural gradient (Markworth et al, 1995); phase segregation arising as a result of centrifugal casting (Fukui and Yamanaka, 1993); property degradation of the fuel cladding in nuclear reactors (Subbaraman and Reifsnider, 1976); chemical and vapor deposition (Freund and Suresh, 2003); and surface modification using laser technology (Picasso et al, 1994;Islam, 1996).…”

“…The use of functionally graded materials has been increasing and these inhomogeneous solids have received considerable scientific attention (Noda, 1999;Fukui and Yamanaka, 1993;Markworth et al, 1995;Ichikawa, 2001;Jeon et al, 1998;Picasso et al, 1994;Islam, 1996;Freund and Suresh, 2003). These composites are designed so that their material properties vary with position to produce a nearly optimal elastic field.…”