Evolution of residual stress behavior in selective laser melting (SLM) of 316L stainless steel through preheating and in-situ re-scanning techniques

Waqar, Saad; Guo, Kai; Sun, Jie

doi:10.1016/j.optlastec.2021.107806

Cited by 53 publications

(14 citation statements)

References 47 publications

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“…LPBF is preferred over other AM processes for a variety of reasons, including the feature that it is a "single-step" process that does not require any special post-processing processes. Throughout one-step powder bed fusion by complete melting, the laser beam causes the deposited material powder to heat and fully melt (Deckers et al, 2014b;Dezfoli et al, 2021a;Waqar et al, 2021a;Dezfoli et al, 2021b;Waqar et al, 2022). However, the whole system produces a very high-temperature gradient and residual stresses due to the rapid heating and cooling of printed layers (Sing et al, 2017;Waqar et al, 2021b;Korkmaz et al, 2022b;Khan et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Additive manufacturing of Al2O3 ceramics with MgO/SiC contents by laser powder bed fusion process

et al. 2023

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Laser powder bed fusion is a laser-based additive manufacturing technique that uses a high-energy laser beam to interact directly with powder feedstock. LPBF of oxide ceramics is highly desirable for aerospace, biomedical and high-tech industries. However, the LPBF of ceramics remains a challenging area to address. In this work, a new slurry-based approach for LPBF of ceramic was studied, which has some significant advantages compared to indirect selective laser sintering of ceramic powders. LPBF of Al2O3 was fabricated at different MgO loads up to 80 wt%. Several specimens on different laser powers (70 W–120 W) were printed. The addition of magnesia influenced the microstructure of the alumina ceramic significantly. The findings show that when the laser power is high and the magnesia load is low, the surface quality of the printing parts improves. It is feasible to produce slurry ceramic parts without binders through LPBF. Furthermore, the effects of SiC and MgO loads on the microstructure and surface morphology of alumina are compared and analysed.

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Section: Introductionmentioning

confidence: 99%

Additive manufacturing of Al2O3 ceramics with MgO/SiC contents by laser powder bed fusion process

et al. 2023

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“…The maximum stress distribution along the x and y components for Model 1 is also shown in the inset of Figure 10. Previous research has also shown that large strains exist along the scanning direction, which is along the x -axis (Waqar et al , 2022).…”

Section: Resultsmentioning

confidence: 98%

Evolution of temperature and residual stress behavior in selective laser melting of 316L stainless steel across a cooling channel

Khan

Waqar

Koç

2022

RPJ

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Purpose The current investigation aims at observing the influence of the cooling channel on the thermal and residual stress behavior of the selective laser melting (SLM)316L uni-layer thermo-mechanical model. Design/methodology/approach On a thermo-mechanical model with a cooling channel, the effect of scanning direction, parallel and perpendicular and scan spacing was simulated. The effect of underlying solid and powder bases was evaluated on residual stress profile and thermal variables at various locations. Findings The high heat dissipation of solid base due to high cooling rates and steep thermal gradients can reciprocate with smaller melt pool temperature and melt pool size. Given the same scan spacing, residual stresses were found lower when laser scanning was perpendicular to the cooling channel. Moreover, large scan spacing was found to increase residual stresses. Originality/value Cooling channels are increasingly being used in additive manufacturing; however, their effect on the residual stress behavior of the SLM component is not extensively studied. This research can serve as a foundation for further inquiries into the impact of base material design such as cooling channels on manufactured components using SLM.

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“…[6,7] The 3D technology can better solve the problem that traditional processing technology is difficult to form. However, in the process of 3D printing forming, the rapid melting and solidification cycles during each layer will result in a large number of residual stresses in the final part, [8] and it is unable to meet the manufacturing requirements of high-performance parts.…”

Section: Introductionmentioning

confidence: 99%

Effect of Shot Peening Strengths on Microstructure and Mechanical Properties of 316L Stainless Steel Prepared by 3D Printing

et al. 2023

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Herein, the influence of shot peening (SP) on the microstructure and mechanical properties of 3D printed 316L stainless steel is studied by optical microscopy (OM), electron backscattered diffraction (EBSD), and mechanical properties testing. The changes in microstructure and mechanical properties of 316L stainless steel by 3D printing under different SP strengths are explored, which are drawn as follows: 1) the microstructure of 3D‐printed 316L stainless steel is greatly refined, and the thickness of ultrafine microstructure in the surface layer increases from 0 to 112.5 μm with the increase in peening strengths from 0 to 0.4 MPa; 2) with the increase of peening strengths from 0 to 0.4 MPa, the hardness increases from 236 to 518 HV, and yield strength increases from 547.3 to 740.7 MPa; and 3) based on the EBSD results, the enhanced hardness and yield strength are caused by refinement hardening and dislocation hardening for the SP samples. In addition, it should be noted that the SP decreases the elongation of 3D‐printed 316L stainless steel up to 9%, and makes the ultimate tensile strength reach the maximum value of 871.2 MPa at 0.2 MPa SP strength.

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Evolution of residual stress behavior in selective laser melting (SLM) of 316L stainless steel through preheating and in-situ re-scanning techniques

Cited by 53 publications

References 47 publications

Additive manufacturing of Al2O3 ceramics with MgO/SiC contents by laser powder bed fusion process

Additive manufacturing of Al2O3 ceramics with MgO/SiC contents by laser powder bed fusion process

Evolution of temperature and residual stress behavior in selective laser melting of 316L stainless steel across a cooling channel

Effect of Shot Peening Strengths on Microstructure and Mechanical Properties of 316L Stainless Steel Prepared by 3D Printing

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