Electro-Optic Shape Measurement of Free-Form Surfaces

Shellabear, Michael C.; Langer, H.-J.

doi:10.1007/978-3-642-84736-3_22

Cited by 3 publications

(2 citation statements)

References 2 publications

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“…The first LB-PBF technology was developed initially for polymer materials by Carl Deckard in 1986 and commercialized by DTM Corporation in 1992. In 1995, the first commercial metal sintering machine was introduced by the EOS company (Shellabear and Nyrhilä, 2004). In this technology, according to Figure 2, metal powder is either fed by a reservoir or hopper and a recoater blade spreads the powder over the build platform.…”

Section: Principles and Processesmentioning

confidence: 99%

Laser subtractive and laser powder bed fusion of metals: review of process and production features

Khorasani¹,

Gibson

Ghasemi³

et al. 2023

RPJ

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Purpose The purpose of this study is, to compare laser-based additive manufacturing and subtractive methods. Laser-based manufacturing is a widely used, noncontact, advanced manufacturing technique, which can be applied to a very wide range of materials, with particular emphasis on metals. In this paper, the governing principles of both laser-based subtractive of metals (LB-SM) and laser-based powder bed fusion (LB-PBF) of metallic materials are discussed and evaluated in terms of performance and capabilities. Using the principles of both laser-based methods, some new potential hybrid additive manufacturing options are discussed. Design methodology approach Production characteristics, such as surface quality, dimensional accuracy, material range, mechanical properties and applications, are reviewed and discussed. The process parameters for both LB-PBF and LB-SM were identified, and different factors that caused defects in both processes are explored. Advantages, disadvantages and limitations are explained and analyzed to shed light on the process selection for both additive and subtractive processes. Findings The performance of subtractive and additive processes is highly related to the material properties, such as diffusivity, reflectivity, thermal conductivity as well as laser parameters. LB-PBF has more influential factors affecting the quality of produced parts and is a more complex process. Both LB-SM and LB-PBF are flexible manufacturing methods that can be applied to a wide range of materials; however, they both suffer from low energy efficiency and production rate. These may be useful when producing highly innovative parts detailed, hollow products, such as medical implants. Originality value This paper reviews the literature for both LB-PBF and LB-SM; nevertheless, the main contributions of this paper are twofold. To the best of the authors’ knowledge, this paper is one of the first to discuss the effect of the production process (both additive and subtractive) on the quality of the produced components. Also, some options for the hybrid capability of both LB-PBF and LB-SM are suggested to produce complex components with the desired macro- and microscale features.

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Section: Principles and Processesmentioning

confidence: 99%

Laser subtractive and laser powder bed fusion of metals: review of process and production features

Khorasani¹,

Gibson

Ghasemi³

et al. 2023

RPJ

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“…Most SLM machines, such as the EOSINT M 270, focus the laser energy to a relatively small spot size of 100 μm with energy intensity values reaching 25 kW mm −2 for a 200 W source. 15 The material thermal response to the heat source tracks the energy source as a function of both space and time. The powder exposed by the laser quickly heats up and then cools down due to the dynamics of the process.…”

Section: Introductionmentioning

confidence: 99%

Comparison of 3DSIM thermal modelling of selective laser melting using new dynamic meshing method to ANSYS

Zeng

Pal

Gong

et al. 2015

Materials Science and Technology

102

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Selective laser melting (SLM) is an additive manufacturing (AM) process in which parts are fabricated by selectively melting regions of the surface of a metallic powder bed in a layer-bylayer fashion. Various thermal phenomena such as heat conduction, convection, radiation, melting and solidification, dynamic phase changes, and evaporation occur during the SLM process. In addition, laser intensity and powder bed scan speeds during processing complicate understanding of the process due to complex dynamic interactions between the powder bed and laser. In order to study these dynamic interactions, a finite element model has been developed which uses a dynamic mesh with spatial non-linear thermal properties to track the point of laser exposure on the powder bed to study thermal evolution during SLM. The model is able to achieve a refined, localised mesh in the melt zone and heat affected zone (HAZ), surrounded by a relatively coarse mesh outside of the HAZ regions. The dynamic meshing for this implementation is achieved using both the sub-modelling functionality in ANSYS and a new set of algorithms being commercialised by 3DSIM, LLC. It was found that dynamic meshing reduces the model size and computational burden. In this paper, the use of the sub-modelling approach for dynamic meshing was verified by comparing it against a uniform fine mesh model. The results of the two models match within an acceptable tolerance. Also, a mesh sensitivity analysis was carried out in order to show solution convergence as a function of increasing mesh density. The results of this analysis were also validated using experiments to show a match between experimental and simulated melt pools. Finally, the ANSYS solution was compared with a new set of dynamic meshing finite element analysis algorithms running in Matlab. It was found that these new algorithms were significantly faster than their ANSYS counterparts for solving problems using a dynamic mesh.

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Integration of Projection Moiré with Coordinate Measuring Machines

Shellabear

Rönner

1994

Laser in Der Technik / Laser in Engineering

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Electro-Optic Shape Measurement of Free-Form Surfaces

Cited by 3 publications

References 2 publications

Laser subtractive and laser powder bed fusion of metals: review of process and production features

Laser subtractive and laser powder bed fusion of metals: review of process and production features

Comparison of 3DSIM thermal modelling of selective laser melting using new dynamic meshing method to ANSYS

Integration of Projection Moiré with Coordinate Measuring Machines

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