Numerical Prediction of Melt Pool Size and Defect Appearing During Selective Laser Melting Process of AlSi10Mg at Various Scan Speeds

2021 ◽  
pp. 226-234
Author(s):  
Mouna Ben Slama ◽  
Sami Chatti
Keyword(s):  
Selective Laser Melting ◽  
Melting Process ◽  
Numerical Prediction ◽  
Pool Size ◽  
Laser Melting ◽  
Selective Laser Melting Process ◽  
Melt Pool ◽  
Melt Pool Size

Estimation of melt pool size by complementary use of external illumination and process emission in coaxial monitoring of selective laser melting

2019 ◽  
Vol 31 (2) ◽  
pp. 022305 ◽  
Author(s):  
Matteo Pacher ◽  
Luca Mazzoleni ◽  
Leonardo Caprio ◽  
Ali Gökhan Demir ◽  
Barbara Previtali
Keyword(s):  
Selective Laser Melting ◽  
Pool Size ◽  
Laser Melting ◽  
Melt Pool ◽  
Melt Pool Size

Numerical Investigation of Selective Laser Melting Process for 904L Stainless Steel

2012 ◽  
Author(s):  
Miranda Fateri ◽  
Andreas Gebhardt ◽  
Maziar Khosravi
Keyword(s):  
Heat Flux ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
Melting Process ◽  
Full Density ◽  
Laser Melting ◽  
Scanning Velocity ◽  
Selective Laser Melting Process ◽  
Fine Mesh ◽  
Melt Pool

Selective Laser Melting process (SLM) is an important manufacturing method for producing complex geometries which allows for creation of full density parts with similar properties as the bulk material without extensive post processing. In SLM process, laser power, beam focus diameter, and scanning velocity must be precisely set based on the material properties in order to produce dense parts. In this study, Finite Element Analysis (FEA) method is employed in order to simulate and analyze a single layer of 904L Stainless Steel. A three-dimensional transient thermal model of the SLM process based on phase change enthalpy, irradiation scattering, and heat conductivity of powder is developed. The laser beam is modeled as a moving heat flux on the surface of the layer using a fine mesh which allows for a variation of the shape and distribution of the beam. In this manner, various Gaussian distributions are investigated and compared against single and multi-element heat flux sources. The melt pool and temperature distribution in the part are numerically investigated in order to determine the effects of varying laser intensity, scanning velocity as well as preheating temperature. The results of the simulation are verified by comparing the melt pool width as a function of power and velocity against the experimentally obtained results. Lastly, 3D objects are fabricated with a SLM 50 Desktop machine using the acquired optimized process parameters.

scholarly journals Numerical Investigation of Thermo-Mechanical Field during Selective Laser Melting Process with Experimental Validation

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1003
Author(s):  
Lan Li ◽  
Frank Liou
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
Thermal Stresses ◽  
Pool Size ◽  
Solidification Structure ◽  
Temperature History ◽  
304L Stainless Steel ◽  
Laser Melting ◽  
Melt Pool ◽  
Melt Pool Size

In this study, thermo-mechanical simulation was conducted to predict thermal and stress behavior in Selective Laser Melting (SLM). Temperature-dependent material properties for processed material 304L stainless steel were incorporated into the model in order to capture the change from powder to fully dense solid stainless steel. Temperature and thermal stress history were tracked under conditions of different parameter sets which were designed to reduce defect formation. The thermal model predicted the temperature history for multi-track scans under different process parameters, such as laser power, effective scanning speed and hatch spacing. Subsequently, the corresponding melt-pool size, solidification rate and temperature gradients could be calculated from simulated temperature data. These three parameters from the simulation were compared with experimental melt pool size, grain structure and cell spacing data obtained from a Renishaw AM250. The experimental data were also used to determine unknown simulation parameters required by the continuum model, e.g., the optical penetration depth and thermal conductivity multiplier for the molten region. This allowed the simulation model to accurately predict melt pool size and solidification structure of SLM 304L stainless steel. Simulated stress showed that the subsequent thermal cyclic melting in successive scanned tracks resulted in alternating compressive and tensile thermal stresses. This work will provide insight for studying microstructure morphology, residual stress and deformations in the SLM process of 304L stainless steel.

Characteristic length of the solidified melt pool in selective laser melting process

2017 ◽  
Vol 23 (2) ◽  
pp. 370-381 ◽  
Author(s):  
Il Hyuk Ahn ◽  
Seung Ki Moon ◽  
Jihong Hwang ◽  
Guijun Bi
Keyword(s):  
Selective Laser Melting ◽  
Characteristic Length ◽  
Melting Process ◽  
Evaluation Methods ◽  
Laser Melting ◽  
Content Type ◽  
Selective Laser Melting Process ◽  
Melt Pool ◽  
Scan Modes ◽  
Hatch Spacing

Purpose This paper aims to propose methods to evaluate the characteristic length of the melt pool for accurate fabrication and to identify the optimal process parameters in the selective laser melting process. Design/methodology/approach Specimens with the types of the scans by controlling the degree of the overlap with hatch spacing are fabricated. The scan modes are classified by statistically analyzing the results of hardness tests. According to the classification of the scans, the evaluation methods are proposed based on the observation of the shape of the solidified melt pool. Findings The control of the hatch spacing can reproduce all modes of the scan conditions, and hardness can be used to classify the scan modes. Originality/value The proposed evaluation methods are based on the analysis of the experimental observation so that they can be easily used for the real evaluation.

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