Influence of process parameters on heat transfer of molten pool for selective laser melting

2021 ◽  
Vol 193 ◽  
pp. 110388
Author(s):  
Yong-Hao Siao ◽  
Chang-Da Wen
Keyword(s):  
Heat Transfer ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Molten Pool ◽  
Laser Melting ◽  
Influence Of Process Parameters

scholarly journals The Influence of Process Parameters and Scanning Strategy on Lower Surface Quality of TA15 Parts Fabricated by Selective Laser Melting

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1228
Author(s):  
Junjie Jiang ◽  
Jianming Chen ◽  
Zhihao Ren ◽  
Zhongfa Mao ◽  
Xiangyu Ma ◽  
...  
Keyword(s):  
Surface Quality ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Flexible Manufacturing ◽  
Molten Pool ◽  
Lower Surface ◽  
Laser Melting ◽  
Scanning Strategy ◽  
Influence Of Process Parameters

With superior flexible manufacturing capability, selective laser melting (SLM) has attracted more and more attention in the aerospace, medical, and automotive industries. However, the poor quality of the lower surface in overhanging structures is still one of the factors that limits the wide application of SLM. In this work, the influence of process parameters and scanning strategy on the lower surface quality of SLMed TA15 (Ti-6Al-2Zr-1Mo-1V) titanium alloy parts were studied. The results showed that the laser surface energy density (EF) had a significant influence on the quality of the lower surface. Excessive EF led to obvious sinking of the molten pool and a serious slag hanging phenomenon. However, the too low EF easily contributed to the insufficient powder fusion in the lower surface area, which led to the agglomeration of a molten pool during core processing, resulting in slag hanging, pores, and powder spalling that reduced the quality of the lower surface. Moreover, the cross-remelting strategy and non-remelting strategy gained better surface quality at the low EF and high EF, respectively. In addition, it was found that the quality of the lower surface could be quickly and accurately evaluated by the cooling time of the molten pool during the processing of the lower surface. This research can increase the understanding of the forming mechanism of the lower surface and has certain guiding significance for the process optimization of the lower surface.

scholarly journals Numerical Simulation of Moving Heat Flux during Selective Laser Melting of AlSi25 Alloy Powder

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 877
Author(s):  
Cong Ma ◽  
Xianshun Wei ◽  
Biao Yan ◽  
Pengfei Yan
Keyword(s):  
Numerical Simulation ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Molten Pool ◽  
Laser Power ◽  
Scanning Speed ◽  
Powder Layer ◽  
Maximum Temperature ◽  
Three Dimensional Model ◽  
Laser Melting

A single-layer three-dimensional model was created to simulate multi-channel scanning of AlSi25 powder in selective laser melting (SLM) by the finite element method. Thermal behaviors of laser power and scanning speed in the procedure of SLM AlSi25 powder were studied. With the increase of laser power, the maximum temperature, size and cooling rate of the molten pool increase, while the scanning speed decreases. For an expected SLM process, a perfect molten pool can be generated using process parameters of laser power of 180 W and a scanning speed of 200 mm/s. The pool is greater than the width of the scanning interval, the depth of the molten pool is close to scan powder layer thickness, the temperature of the molten pool is higher than the melting point temperature of the powder and the parameters of the width and depth are the highest. To confirm the accuracy of the simulation results of forecasting excellent process parameters, the SLM experiment of forming AlSi25 powder was carried out. The surface morphology of the printed sample is intact without holes and defects, and a satisfactory metallurgical bond between adjacent scanning channels and adjacent scanning layers was achieved. Therefore, the development of numerical simulation in this paper provides an effective method to obtain the best process parameters, which can be used as a choice to further improve SLM process parameters. In the future, metallographic technology can also be implemented to obtain the width-to-depth ratio of the SLM sample molten pool, enhancing the connection between experiment and theory.

Adjustment of the scan track spacing and linear input energy to fabricate dense, pseudoelastic Nitinol shape memory alloy parts by selective laser melting

2021 ◽  
pp. 1045389X2110639
Author(s):  
Mohammadreza Zamani ◽  
Mahmoud Kadkhodaei ◽  
Mohsen Badrossamay ◽  
Ehsan Foroozmehr
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Room Temperature ◽  
Optimal Parameters ◽  
Research Groups ◽  
Laser Melting ◽  
Influence Of Process Parameters ◽  
Transformation Temperatures

Nitinol is a well-known shape memory alloy (SMA) which is widely used due to its unique properties such as shape memory effect and pseudoelasticity. However, challenges fabricating Nitinol parts have limited the use of this alloy. Nowadays, additive manufacturing methods, specifically selective laser melting (SLM), are being used as an alternative to conventional methods for fabricating Nitinol specimens. Achieving a dense structure and controlling the transformation temperatures in such products have been among the most important challenges for several research groups. In the present study, fabrication of dense Nitinol parts by SLM together with control of their transformation temperatures is investigated with the main purpose of achieving pseudoelastic products at room temperature. For this purpose, the effect of process parameters on density, transformation temperatures, microstructure, hardness, and shape memory response are studied. The influence of process parameters on transformation temperatures varies depending on the amount of power so that the effect of scan tracks spacing for high powers is more pronounced than that for low powers. The hardness and compressive strength of the parts are also affected by the process parameters. Accordingly, optimal parameters are found to fabricate dense pseudoelastic parts with the ability of strain recovery at ambient temperature.

Selective Laser Melting of the Inconel 718 Nickel Superalloy

2014 ◽  
Vol 698 ◽  
pp. 333-338 ◽  
Author(s):  
Vadim Sh. Sufiiarov ◽  
Evgenii V. Borisov ◽  
Igor A. Polozov
Keyword(s):  
Selective Laser Melting ◽  
Process Parameters ◽  
Inconel 718 ◽  
Melting Process ◽  
Nickel Superalloy ◽  
Mechanical Tests ◽  
Laser Melting ◽  
Influence Of Process Parameters ◽  
Inconel 718 Superalloy

The results of the research on selective laser melting process of the Inconel 718 superalloy powder under conditions of additive manufacturing of parts for special purposes are presented. The influence of process parameters on the quality of manufactured parts is shown. Process parameters which allow manufacturing parts with the density close to 100%, are determined. Also, the results of mechanical tests and investigation of microstructure are presented.

scholarly journals Effect of Selective Laser Melting Process Parameters on Microstructure and Properties of Co-Cr Alloy

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1546 ◽  
Author(s):  
Jian-Hong Wang ◽  
Jie Ren ◽  
Wei Liu ◽  
Xiao-Yu Wu ◽  
Ming-Xiang Gao ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Process Parameters ◽  
Molten Pool ◽  
Laser Energy ◽  
Melting Process ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Laser Melting ◽  
The Relationship ◽  
Cobalt Chromium Alloy

Due to the rapid melting and solidification mechanisms involved in selective laser melting (SLM), CoCrMo alloys fabricated by SLM differ from the cast form of the same alloy. In this study, the relationship between process parameters and the morphology and macromechanical properties of cobalt-chromium alloy micro-melting pools is discussed. By measuring the width and depth of the molten pool, a theoretical model of the molten pool is established, and the relationship between the laser power, the scanning speed, the scanning line spacing, and the morphology of the molten pool is determined. At the same time, this study discusses the relationship between laser energy and molding rate. Based on the above research, the optimal process for the laser melting of cobalt-chromium alloy in the selected area is obtained. These results will contribute to the development of biomedical CoCr alloys manufactured by SLM.

DoE Applied to Thermal Analysis and Simulation of Geometrical Stability of a Wind Turbine Blade Made by Selective Laser Melting

2021 ◽  
Vol 1161 ◽  
pp. 65-74
Author(s):  
Abbas Razavykia ◽  
Eugenio Brusa ◽  
Sina Ghodsieh ◽  
Lorenzo Giorio
Keyword(s):  
Wind Turbine ◽  
Selective Laser Melting ◽  
Turbine Blade ◽  
Process Parameters ◽  
Thermal Stresses ◽  
Wind Turbine Blade ◽  
Powder Layer ◽  
Laser Melting ◽  
Influence Of Process Parameters ◽  
Wide Range

The Selective Laser Melting (SLM) is one of the most demanding additive manufacturing(AM) processes, although it assures some superior advantages in producing complex structural componentsand applies to a wide range of materials. The control of SLM parameters is crucial to guaranteethe quality of manufactured component. The steep thermal variation in part during the SLM processinduces some undesired effects, such as warping, residual thermal stresses and microcracks,as wellas geometrical instability. Effectively predicting the influence of process parameters upon the productquality of part made by SLM is extremely useful in the earliest steps of design, especially whena higher productivity is required. Particularly, thermal simulation is used to suitably calibrate someprocess parameters, to improve efficiency and reduce defects. Besides, such simulation is exploited toimprove the heat transfer between the bed and the first product layer, to reduce thermal stress and theoverall product deformation. This study exemplifies how numerical modeling of temperature distributionin a wind turbine blade made by SLM allows predicting the dimensional stability. The Design ofExperiments (DoE) and ANOVA analysis helped in studying effects on the product geometric stabilityand deformation, of some process parameters, as powder layer thickness, hatch space and laser scanspeed.

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