• JLA Vol:16 Iss:3 (Laser synthesizing NiAl intermetallic and TiC reinforced NiAl intermetallic matrix composite)


    Authors:
    Minlin Zhong
    Laser Processing and Rapid Prototyping Research Center, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China

    Xiangyang Xu
    Laboratory for Surface Modification, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China

    Wenjin Liu
    Hongqing Sun
    Laser Processing and Rapid Prototyping Research Center, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China


    The NiAl intermetallic layers and NiAl matrix composite layers with TiC particulate reinforcement were successfully synthesized by laser cladding with coaxial powder feeding of Ni/Al clad p...

    $25.00

  • JLA Vol:16 Iss:3 (Laser-assisted chemical vapor deposition to directly write three-dimensional microstructures)


    Authors:
    S. I. Han
    S. H. Jeong
    Department of Mechatronics, Kwangju Institute of Science and Technology, 1 Oryongdong Pukgu, Kwangju 500-712, South Korea


    Application of laser-assisted chemical vapor deposition to the fabrication of three-dimensional microstructures is investigated. To fabricate a three-dimensional microstructure, a thin layer of deposit in desired patterns is first written on a flat substrate using the laser-direct-writing technique and on top of this layer a second layer is deposited to increase the height of the deposit pattern. After repeatedly depositing several layers in the same manner, a three-dimensional microstructure is fabricated. Optimum deposi...

    $25.00

  • JLA Vol:16 Iss:3 (Methods for hazard assessment from viewing fiber optics with eye loupes)


    Authors:
    Wesley J. Marshall
    U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland 21010-5403

    John Bell
    Terabeam Corporation, Redmond, Washington

    David H. Sliney
    U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland 21010-5403


    Current laser safety standards overestimate retinal hazards when viewing optical fiber tips with magnifying aids. Methods for assessing optical hazards are based on laser beam characteristics and assume worst-case exposure to both the unaided eye and when using a variety of optical aids. These standard methods provide overly conservati...

    $25.00

  • JLA Vol:16 Iss:3 (Solidification model of laser cladding with wire feeding technique)


    Authors:
    Chien-Fu Hung
    Jehnming Lin
    Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan


    The object of this study is to investigate the solidification problem in laser cladding with the wire feeding technique. The solidification phenomenon of laser cladding was analyzed by numerical simulation and experimental visualization. Good agreement has been obtained for 304 stainless steel wires cladding on round tubes and it transpires that there were three basic modes of clad profiles: thinning, thickening, and wavering of the clad thickness at different velocity settings between the feeding wire and the substrate in laser wire cladding. &copy...

    $25.00

  • 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 Kong


    A 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, Germany


    CO2 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...

    $25.00

  • 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 65409-1060


    Laser 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 ...

    $25.00

  • 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, Singapore


    The 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...

    $25.00

  • 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 16802


    Laser 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...

    $25.00

  • 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, China


    Rapid 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...

    $25.00

Pages

help desk software

There is currently no content classified with this term.