Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - An experimental and numerical study of the influence of diode laser beam shape on thin wall direct metal deposition
AU - Pinkerton, Andrew J.
AU - Li, L.
PY - 2005
Y1 - 2005
N2 - Use of the high powered diode laser (HPDL) for direct metal deposition enables multiple layer cladding to be performed with a nominally rectangular beam, traversed at different angles to the fast axis, or with a fiber-coupled, circular beam. These factors may provide an advantage over the traditional beam profiles of CO2 and Nd:YAG lasers, so there is a need to examine the effect that they have on the process and final product characteristics. This article reports such an examination. A 1.5 kW HPDL and 316 L stainless steel powder are used to experimentally investigate the dimensions, microstructure, surface finish, and hardness of multiple layer walls produced using nominally rectangular and circular beams under a range of conditions. The diode beam profiles are modeled using a "Gaussian beam array" method for the nominally rectangular beam and a "concentric series" method for the fiber-coupled beam. Quasistationary state temperature profiles are produced for both beam shapes by superposition of Gaussian source solutions. The experimental results show little difference in microstructural properties, elemental composition, or hardness due to beam shape or traverse direction, but track dimensions are dependent on beam geometry. Wall width is particularly dependent on beam size orthogonal to the traverse direction. Modeling allows some of the results encountered to be explained in terms of temperature distributions and cooling rates. Fiber coupling seems to provide a benefit if even thin-wall dimensions are required for applications such as rapid prototyping, while using the rectangular beam provides advantages for bulk material addition for applications such as repair and refurbishment of worn components. (C) 2005 Laser Institute of America.
AB - Use of the high powered diode laser (HPDL) for direct metal deposition enables multiple layer cladding to be performed with a nominally rectangular beam, traversed at different angles to the fast axis, or with a fiber-coupled, circular beam. These factors may provide an advantage over the traditional beam profiles of CO2 and Nd:YAG lasers, so there is a need to examine the effect that they have on the process and final product characteristics. This article reports such an examination. A 1.5 kW HPDL and 316 L stainless steel powder are used to experimentally investigate the dimensions, microstructure, surface finish, and hardness of multiple layer walls produced using nominally rectangular and circular beams under a range of conditions. The diode beam profiles are modeled using a "Gaussian beam array" method for the nominally rectangular beam and a "concentric series" method for the fiber-coupled beam. Quasistationary state temperature profiles are produced for both beam shapes by superposition of Gaussian source solutions. The experimental results show little difference in microstructural properties, elemental composition, or hardness due to beam shape or traverse direction, but track dimensions are dependent on beam geometry. Wall width is particularly dependent on beam size orthogonal to the traverse direction. Modeling allows some of the results encountered to be explained in terms of temperature distributions and cooling rates. Fiber coupling seems to provide a benefit if even thin-wall dimensions are required for applications such as rapid prototyping, while using the rectangular beam provides advantages for bulk material addition for applications such as repair and refurbishment of worn components. (C) 2005 Laser Institute of America.
KW - laser deposition
KW - semiconductor lasers
KW - optical fibre cladding
KW - optical fibre couplers
KW - gas lasers
KW - neodymium
KW - solid lasers
KW - stainless steel
KW - rapid prototyping (industrial)
KW - layered manufacturing
KW - Gaussian processes
KW - rapid prototyping
KW - laser cladding
KW - diode laser
KW - modeling
KW - heat source
U2 - 10.2351/1.1848533
DO - 10.2351/1.1848533
M3 - Journal article
VL - 17
SP - 47
EP - 56
JO - Journal of Laser Applications
JF - Journal of Laser Applications
SN - 1042-346X
IS - 1
ER -