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Y P Kathuria - One of the best experts on this subject based on the ideXlab platform.

  • 3D microstructuring by selective laser sintering/microcladding of Metallic Powder
    Computer-Controlled Microshaping, 1999
    Co-Authors: Y P Kathuria
    Abstract:

    This paper describes two processes for the 3D microstructuring of Metallic/metal-matrix composite parts by using pulsed Nd-YAG laser. (1) In the first part, laser microcladding process is discussed. The effect of beam interaction time and the relationship between various layers are considered. The results show that in this case the beam interaction time greatly affect the structural development of the product with respect to its strength and quality. (2) In the second part, selective laser sintering with the one and two components Metallic Powders shall be discussed. The results show that due to the surface contact only, the feature size obtained with the one component solid state sintering is smaller compared to the two metal liquid phase sintering of the Metallic Powder, comprising of high and low melting point. The influence of the processing conditions on the type of phases and the microstructure evaluation are considered. Successful attempts were also made in creating the fine structures with the metal-matrix composite Powder materials. A few examples are demonstrated briefly.

  • Microstructuring by selective laser sintering of Metallic Powder
    Surface & Coatings Technology, 1999
    Co-Authors: Y P Kathuria
    Abstract:

    Abstract This paper describes recent work carried out on three-dimensional microstructuring by beam technology — both one-component solid-state laser sintering and two-metal liquid-phase selective laser sintering of Metallic Powders with high and low melting points. The results show that, due to the surface contact only, the feature size obtained with one-component solid-state sintering is smaller than that with two-metal liquid-phase sintering. The influence of the processing conditions on the type of phases and microstructure evolution are considered. Attempts were also made to create fine structures with the composite Powder materials. A few brief examples are demonstrated.

  • Laser microfabrication of Metallic parts
    Rapid Prototyping and Flexible Manufacturing, 1997
    Co-Authors: Y P Kathuria
    Abstract:

    In this paper two processes of microfabrication technology are investigated. In the first part, laser generating process which is largely affected by the beam interaction time is described. In the second part, selective laser sintering of Metallic Powder shall be discussed. The results show that the two metal liquid phase sintering is most effective in the selective laser sintering of the Metallic Powder comprising of high and low melting point. Whereas in the generating process the beam interaction time greatly affect the structural development of the product with respect to its strength and quality. A few examples are demonstrated briefly.

  • Selective laser sintering of Metallic Powder for microfabrication technology
    1997 International Symposium on Micromechanics and Human Science (Cat. No.97TH8311), 1
    Co-Authors: Y P Kathuria
    Abstract:

    This paper describes the 3D micro-structuring by beam technology, which employ the one component solid state and two metal liquid phase selective laser sintering of Metallic Powder comprising of high and low melting point temperature. The influence of the processing conditions on the type of phases and the microstructure evolution are considered.

H.p. Weber - One of the best experts on this subject based on the ideXlab platform.

  • High precision pulsed selective laser sintering of Metallic Powders
    Advanced Laser Technologies 2004, 2005
    Co-Authors: P Fischer, Andreas Blatter, V. Romano, H.p. Weber
    Abstract:

    The generative process of selective laser sintering of Powders such as Titanium, Platinum alloys and steel can in comparison to cw radiation significantly be improved by using pulsed radiation. With an appropriate energy deposition in the Metallic Powder layer, the material properties of the selective laser sintered parts can locally be tailored to the requirements of the finished work piece. By adapting the laser parameters of a Q-switched Nd:YAG laser, notably pulse duration and local intensity, the degree of porosity, density and even the crystalline microstructure can be controlled. Pulsed interaction allows minimizing the average power needed for consolidation of the Metallic Powder, and leads to less residual thermal stresses. With laser post processing, the surface can achieve bulk-like density. Furthermore, we present the possibility of forming Metallic glass components by sintering amorphous Metallic Powders.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

  • Highly precise pulsed selective laser sintering of Metallic Powders
    Laser Physics Letters, 2005
    Co-Authors: P Fischer, Andreas Blatter, V. Romano, H.p. Weber
    Abstract:

    We studied the influence of the laser parameters on the material properties of selectively laser sintered Titanium and Platinum-alloyed Powders, which are both of paramount interest in modern technology. In this article, we show that with an appropriate energy deposition in the Metallic Powder layer, the material properties of the selectively laser sintered parts can locally be tailored to the requirements of the finished work piece. By adapting the laser parameters of a Q-switched Nd: YAG laser, notably pulse duration and local intensity, the degree of porosity, density and even the crystalline microstructure can be controlled. Pulsed interaction allows in addition to minimize the average power needed for consolidation of the Metallic Powder, and leads to less residual thermal stresses. With laser post processing, the surface can achieve bulk-like density. We also demonstrate for the first time to our knowledge the highly precise selective laser sintering of steel micro Powder with a lateral accuracy of less than 10 micrometers by using a modelocked Nd:YAG laser. Furthermore, we present the possibility of forming Metallic glass components by sintering amorphous Metallic Powders. © 2005 by Astro Ltd.

I Smurov - One of the best experts on this subject based on the ideXlab platform.

  • energy input effect on morphology and microstructure of selective laser melting single track from Metallic Powder
    Journal of Materials Processing Technology, 2013
    Co-Authors: Igor Yadroitsev, Pavel Krakhmalev, Ina Yadroitsava, Sten Johansson, I Smurov
    Abstract:

    Abstract Process parameters of selective laser melting affect the response of a Powder–substrate system and, therefore, the geometry and microstructure of the manufactured parts. The experiments were carried out at fixed values of laser power (50 W), spot diameter (70 μm) and Powder layer thickness (80 μm). In this research, influence of the energy input parameters (80–900 °C preheating temperature and 0.08–0.28 m/s laser scanning speed) on microstructure and geometry of single tracks fabricated of stainless steel grade 316L Powder was analysed. Both factors were found statistically significant with regard to their influence on the remelted depth and the primary cell spacing in the colonies observed in the tracks cross-sections. More specifically, the contact angle and track height were controlled by the preheating temperature, and track width and contact zone characteristics were governed by the laser scanning speed. Because of the threshold behaviour of these two factors, values starting with 700 °C and 0.24 m/s were found not optimal and causing instability and balling effect. Conclusions regarding the selection of process parameters for the formation of tracks with the desired geometry and microstructure were formulated based on statistical analysis of the experimental data.

  • strategy of manufacturing components with designed internal structure by selective laser melting of Metallic Powder
    Applied Surface Science, 2007
    Co-Authors: Igor Yadroitsev, L Thivillon, Ph Bertrand, I Smurov
    Abstract:

    Abstract Application of selective laser melting for manufacturing three-dimensional objects represents one of the promising directions to solve challenging industrial problems. This approach permits to extend dramatically the freedom of design and manufacture by allowing, for example, to create an object with desired shape and internal structure in a single fabrication step. The design of the part can be tailored to meet specific functions and properties (e.g. physical, mechanical, chemical, biological, etc.) using different materials. Metallic objects were manufactured by Phenix PM 100 machine from Inconel 625 Powder. The objective was to analyze the influence of the manufacturing strategy on the internal structure and mechanical properties of the components manufactured by selective laser melting technology. Anisotropy of the internal structure and mechanical properties of the fabricated objects were studied.

P Fischer - One of the best experts on this subject based on the ideXlab platform.

  • High precision pulsed selective laser sintering of Metallic Powders
    Advanced Laser Technologies 2004, 2005
    Co-Authors: P Fischer, Andreas Blatter, V. Romano, H.p. Weber
    Abstract:

    The generative process of selective laser sintering of Powders such as Titanium, Platinum alloys and steel can in comparison to cw radiation significantly be improved by using pulsed radiation. With an appropriate energy deposition in the Metallic Powder layer, the material properties of the selective laser sintered parts can locally be tailored to the requirements of the finished work piece. By adapting the laser parameters of a Q-switched Nd:YAG laser, notably pulse duration and local intensity, the degree of porosity, density and even the crystalline microstructure can be controlled. Pulsed interaction allows minimizing the average power needed for consolidation of the Metallic Powder, and leads to less residual thermal stresses. With laser post processing, the surface can achieve bulk-like density. Furthermore, we present the possibility of forming Metallic glass components by sintering amorphous Metallic Powders.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

  • Highly precise pulsed selective laser sintering of Metallic Powders
    Laser Physics Letters, 2005
    Co-Authors: P Fischer, Andreas Blatter, V. Romano, H.p. Weber
    Abstract:

    We studied the influence of the laser parameters on the material properties of selectively laser sintered Titanium and Platinum-alloyed Powders, which are both of paramount interest in modern technology. In this article, we show that with an appropriate energy deposition in the Metallic Powder layer, the material properties of the selectively laser sintered parts can locally be tailored to the requirements of the finished work piece. By adapting the laser parameters of a Q-switched Nd: YAG laser, notably pulse duration and local intensity, the degree of porosity, density and even the crystalline microstructure can be controlled. Pulsed interaction allows in addition to minimize the average power needed for consolidation of the Metallic Powder, and leads to less residual thermal stresses. With laser post processing, the surface can achieve bulk-like density. We also demonstrate for the first time to our knowledge the highly precise selective laser sintering of steel micro Powder with a lateral accuracy of less than 10 micrometers by using a modelocked Nd:YAG laser. Furthermore, we present the possibility of forming Metallic glass components by sintering amorphous Metallic Powders. © 2005 by Astro Ltd.

Igor Yadroitsev - One of the best experts on this subject based on the ideXlab platform.

  • energy input effect on morphology and microstructure of selective laser melting single track from Metallic Powder
    Journal of Materials Processing Technology, 2013
    Co-Authors: Igor Yadroitsev, Pavel Krakhmalev, Ina Yadroitsava, Sten Johansson, I Smurov
    Abstract:

    Abstract Process parameters of selective laser melting affect the response of a Powder–substrate system and, therefore, the geometry and microstructure of the manufactured parts. The experiments were carried out at fixed values of laser power (50 W), spot diameter (70 μm) and Powder layer thickness (80 μm). In this research, influence of the energy input parameters (80–900 °C preheating temperature and 0.08–0.28 m/s laser scanning speed) on microstructure and geometry of single tracks fabricated of stainless steel grade 316L Powder was analysed. Both factors were found statistically significant with regard to their influence on the remelted depth and the primary cell spacing in the colonies observed in the tracks cross-sections. More specifically, the contact angle and track height were controlled by the preheating temperature, and track width and contact zone characteristics were governed by the laser scanning speed. Because of the threshold behaviour of these two factors, values starting with 700 °C and 0.24 m/s were found not optimal and causing instability and balling effect. Conclusions regarding the selection of process parameters for the formation of tracks with the desired geometry and microstructure were formulated based on statistical analysis of the experimental data.

  • strategy of manufacturing components with designed internal structure by selective laser melting of Metallic Powder
    Applied Surface Science, 2007
    Co-Authors: Igor Yadroitsev, L Thivillon, Ph Bertrand, I Smurov
    Abstract:

    Abstract Application of selective laser melting for manufacturing three-dimensional objects represents one of the promising directions to solve challenging industrial problems. This approach permits to extend dramatically the freedom of design and manufacture by allowing, for example, to create an object with desired shape and internal structure in a single fabrication step. The design of the part can be tailored to meet specific functions and properties (e.g. physical, mechanical, chemical, biological, etc.) using different materials. Metallic objects were manufactured by Phenix PM 100 machine from Inconel 625 Powder. The objective was to analyze the influence of the manufacturing strategy on the internal structure and mechanical properties of the components manufactured by selective laser melting technology. Anisotropy of the internal structure and mechanical properties of the fabricated objects were studied.