JLA Vol:16 Iss:4 (A finite element method approach for thermal analysis of laser cladding of magnesium alloy with preplaced Al–Si powder)
Authors:
L. F. Guo
T. M. Yue
H. C. Man
The Advanced Manufacturing Technology Research Centre, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong KongA numerical model based on the finite element method (FEM) has been developed to simulate the temperature profile of laser cladding with preplaced metal powders. The FEM model is capable of simulating the three-dimensional thermal field of the cladding zone under the condition of a moving heat source, taking into consideration the thermal contact resistance between the powder bed and the substrate. Verification experiments were conducted by the laser cladding o...
$25.00
JLA Vol:16 Iss:4 (Comprehensive assessment of the CO<sub>2</sub> laser cut quality of ceramics with different assist gas injection systems)
Authors:
F. Quintero
J. Pou
F. Lusquin˜os
M. Boutinguiza
R. Soto
M. Pe´rez-Amor
Departamento Fi´sica Aplicada, Universidade de Vigo, E.T.S. Ingenieros Industriales, Lagoas-Marcosende 9, 36280 Vigo, Spain
F. Wagner
BIAS, Bremen Institute of Applied Beam Technology, Bremen, GermanyCO2 laser cutting is an efficient and advantageous process for cutting of ceramics when the hardness of such materials makes the conventional machining methods unproductive. At the same time, the application of laser cutting to ceramics involves the assessment of the different process parameters...
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JLA Vol:16 Iss:4 (Dimensional and material characteristics of direct deposited H13 tool steel by CO<sub>2</sub> laser)
Authors:
J. Choi
Y. Hua
Department of Mechanical and Aerospace Engineering and Engineering Mechanics, University of Missouri, Rolla, Missouri 65409-1060Laser aided direct metal/material deposition process builds metal parts layer-by-layer directly from the computer aided design representation. Success of this technology in the die and tool industry depends on the parts quality to be achieved. To get designed geometric dimensions and material properties, delicate control of the process variables such as laser power, spot diameter, traverse speed, and powder mass flow rate is critical. With a closed loop optical height control system, the dimensional accuracy was achieved ...
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JLA Vol:16 Iss:4 (Identification of the mechanisms governing modifications of the wettability characteristics of a magnesia partially stabilized zirconia bioceramic following CO<sub>2</sub> laser treatment)
Authors:
L. Hao
J. Lawrence
Manufacturing Engineering Division, School of Mechanical & Production Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, Singapore 639798, SingaporeThe mechanisms responsible for modifying the wettability characteristics of a magnesia partially stabilized zirconia (MgO–PSZ) bioceramic material after CO2 laser treatment have been elucidated. Changes in the contact angle, θ, which characterizes the wettability characteristics of the MgO–PSZ, were attributed primarily to: modifications to the surface roughness of the material, the incorporation of oxygen at the surface, and the increase in the...
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JLA Vol:16 Iss:4 (Laser assisted cleaning of oxide films on SUS409 stainless steel)
Authors:
H. Guo
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
R. Martukanitz
Applied Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802
T. DebRoy
Department of Materials Science and Engineering, The Pennsylvania State Univeristy, University Park, Pennsylvania 16802Laser assisted cleaning of oxide films on SUS409 stainless steel plates was studied both experimentally and theoretically. The highly oxidized surfaces with oxide scales of about 25 μm thickness were irradiated with Q-switched pulsed Nd:yttritium–aluminu...
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JLA Vol:16 Iss:4 (Laser microfabrication with metallic powder)
Authors:
Chen Jimin
Zuo Tiechuan
National Center of Laser Technology, Beijing University of Technology, Beijing 100022, ChinaRapid prototyping (RP) technology has developed fast in the last year. It is an inevitable trend to adopt laser melting metal powder material directly to make metal parts from RP technology to rapid manufacturing. However, at present it is still at the stage of explorlation to utilize micro powder metal material for microfabrication. In this article two methods of microfabrication were investigated. One is selective laser microsintering. Equipment of YAG doubling frequency laser was used to sinter metallis powder materials to fabricate the micro pa...
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JLA Vol:16 Iss:4 (Laser transmission welding of polymer and wood composites: Material and joint mechanism related studies)
Authors:
H. Haferkamp
A. von Busse
S. Barcikowski
A. Ostendorf
J. Bunte
Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, GermanyLaser beam transmission welding is an innovative and promising technology for many industries such as the automotive, electronic, and medical industry. Extension to application of this technology to wood components makes it also interesting for the woodworking and furniture industry. Therefore, several investigations in the field of welding of fiber reinforced thermoplastic and wood composites with polymers have been carried out. Focus is given to the determination of the weldability and weld ...
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JLA Vol:16 Iss:4 (Micromelting and its effects on surface topography and properties in laser polishing of stainless steel)
Authors:
T. A. Mai
G. C. Lim
Machining Technology Group, Singapore Institute of Manufacturing Technology, Singapore 638075, SingaporeThis article presents the results of an investigation into using laser for polishing 304 stainless steel (SS) surfaces. The effects on surface topography, reflectivity, hardness, and corrosion resistance of 304 stainless steel were analyzed. An in-house developed finite difference heat conduction model was used to simulate the rapid melting and solidification process. The nonlinear problem of the solid/liquid moving boundary was solved by a novel hybrid numerical method. Melting depth was in the order of submicrons and polishing rate in a r...
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JLA Vol:16 Iss:4 (Microstructural aspects of laser dissimilar welds of hard metals to steels)
Authors:
A. Costa
IDMEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
L. Quintino
IDMEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal and Instituto Superior Te´cnico, Secc¸a˜o de Tecnologia Mecaˆnica, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
R. M. Miranda
IDMEC, Av. Rovisco Pais, 1049-001 Lisboa, Portugal and Universidade Aberta, R. Escola Polite´cnica 147, 1269-001 Lisboa, PortugalLaser beam welding has been widely used in industry in the past decade. Recently, applications in dissimilar welds involving hard metals have been investigated. Hard metals are commonly used in tool manufacturing and this application...
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JLA Vol:17 Iss:1 (An experimental and numerical study of the influence of diode laser beam shape on thin wall direct metal deposition)
Authors:
Andrew J. Pinkerton
Lin Li
School of Mechanical, Aerospace, and Civil Engineering, The University of Manchester, Sackville Street, Manchester, M60 1QD U.K.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 ...
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