An analysis of the beam interaction characteristics of selected lasers with an alpha-alumina bioceramic

Lawrence, Jonathan

doi:10.1016/s0143-8166(03)00017-4

Cited by 19 publications

(7 citation statements)

References 18 publications

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“…This equipment provides low interaction with ceramics, meaning that low heat efficiency is taking place. Pure alumina is then said to be "almost transparent" with a characteristic absorption length of [27]. This means that radiation can propagate deeply in the material, interaction not being restricted to the vicinity of the surface as it is the case for metallic materials where this characteristic length is lower than [11].…”

Section: Energy Conservation and Heat Source Modelmentioning

confidence: 99%

Three-dimensional finite element thermomechanical modeling of additive manufacturing by selective laser melting for ceramic materials

Chen

Guillemot

Gandin

et al. 2017

Additive Manufacturing

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International audienceA model for additive manufacturing by selective laser melting of a powder bed with application to alumina ceramic is presented. Based on Beer-Lambert law, a volume heat source model taking into account the material absorption is derived. The level set method is used to track the shape of deposed bead. An energy solver is coupled with thermodynamic database to calculate the melting-solidification path. Shrinkage during consolidation from powder to liquid and compact medium is modeled by a compressible Newtonian constitutive law. A semi-implicit formulation of surface tension is used, which permits a stable resolution to capture the liquid/gas interface. The influence of different process parameters on temperature distribution, melt pool profiles and bead shapes is discussed. The effects of liquid viscosity and surface tension on melt pool dynamics are investigated. Three dimensional simulations of several passes are also presented to study the influence of the scanning strategy

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Section: Energy Conservation and Heat Source Modelmentioning

confidence: 99%

Three-dimensional finite element thermomechanical modeling of additive manufacturing by selective laser melting for ceramic materials

Chen

Guillemot

Gandin

et al. 2017

Additive Manufacturing

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“…According to [ 38 ], the preheating laser source

and melting/sintering source

can be described as follows:

where A , I , α,

, and R are the material absorptivity, laser intensity, absorption coefficient, scanning speed, and laser radius, respectively. The absorption coefficient was estimated according to [ 39 , 40 ]. The x and y parameters in Equations (2) and (3) were used to control the laser movement on the powder bed.…”

Section: Methodsmentioning

confidence: 99%

A Novel Approach for Powder Bed Fusion of Ceramics Using Two Laser Systems

et al. 2023

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The one-step AM process is considered the goal many researchers seek in the field of Additive Manufacturing (AM) of high-technology ceramics. Among the several AM techniques, only Powder Bed Fusion (PBF) can directly print high-technology ceramics using one step. However, the PBF technique faces numerous challenges to efficiently be employed in the PBF of ceramics. These challenges include the formation of cracks, generated thermal stress, effective laser–powder interaction, and low acquired relative density. This study developed a new preheating mechanism for ceramic materials using two laser systems to surpass beyond these challenges and successfully print ceramics with a single-step AM method. One laser is used to preheat the powder particles before the second laser is utilised to complete the melting/sintering process. Both lasers travel along the same scanning path. There is a slight delay (0.0001 s) between the preheating laser and the melting/sintering laser to guarantee that the melting/sintering laser scans a properly preheated powder. To further facilitate testing of the preheating system, a numerical model has been developed to simulate the preheating and melting process and to acquire proper process parameters. The developed numerical model was shown to determine the correct process parameters without needing costly and time-consuming experiments. Alumina samples (10 × 10 × 6 mm3) were successfully printed using alumina powder as feedstock. The surface of the samples was nearly defect-free. The samples’ relative densities exceeded 80%, the highest reported relative density for alumina produced by a single-step AM method. This discovery can significantly accelerate the transition to a one-step AM process of ceramics.

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“…Although -values are reported by Lawrence (2004) and Bityukov and Petrov (2013), variations can extend over several orders of magnitude. Alumina shows low absorption of Yb:YAG laser light, and it can be strongly modified by impurities.…”

Section: Volumetric Heat Source Parametersmentioning

confidence: 96%

Additive manufacturing of an oxide ceramic by laser beam melting—Comparison between finite element simulation and experimental results

Moniz

Chen

Guillemot

et al. 2019

Journal of Materials Processing Technology

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et al.. Additive manufacturing of an oxide ceramic by laser beam melting-Comparison between finite element simulation and experimental results. Abstract: Recent progress in the application of Laser Beam Melting (LBM) of oxide ceramics has shown promising results. However, a deeper understanding of the process is required to master and control the track development. In this approach numerical modeling could allow higher quality, of additive manufacturing for such materials, to be achieved. The validation of an earlier developed finite element model for LBM of ceramic materials has been established through a comparison with experimental results. The model solves heat and mass transfers whilst accounting for fluid flow due to surface tension and Marangoni convection, as well as tracking the material/gas boundary. The volumetric heat source parameters used in the simulations have been calibrated with an analytical model combined with original in-situ reflectance measurements. Numerical results show good agreement with measurements of melt pool dimensions and shapes. They also provide a coherent description of the evolution of the track morphology when varying the heat source parameters. Track irregularities have also been revealed by simulations at high scanning speed and the balling effect highlighted and explained through similar simulations.

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An analysis of the beam interaction characteristics of selected lasers with an alpha-alumina bioceramic

Cited by 19 publications

References 18 publications

Three-dimensional finite element thermomechanical modeling of additive manufacturing by selective laser melting for ceramic materials

Three-dimensional finite element thermomechanical modeling of additive manufacturing by selective laser melting for ceramic materials

A Novel Approach for Powder Bed Fusion of Ceramics Using Two Laser Systems

Additive manufacturing of an oxide ceramic by laser beam melting—Comparison between finite element simulation and experimental results

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