Finite element simulation and experimental study of single-laser track in laser polishing of Ti6Al4V

Li, Jiejing; Jin, Yuedong; Chang, Yuqing; Zuo, Dunwen

doi:10.1007/s00170-022-09664-5

Cited by 7 publications

(4 citation statements)

References 25 publications

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“…The cooling rate dropped rapidly, except in the adjacent zone of the molten pool dropped slowly. The simulated values matched the experimental values within 10% errors [28]. A hydrodynamics model was established to understand the CW in LP [29].…”

Section: Numerical Analysismentioning

confidence: 61%

Recent Advancements in Post Processing of Additively Manufactured Metals Using Laser Polishing

Ali

Almotari

Qattawi

2023

JMMP

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The poor surface roughness associated with additively manufactured parts can influence the surface integrity and geometric tolerances of produced components. In response to this issue, laser polishing (LP) has emerged as a potential technique for improving the surface finish and producing parts with enhanced properties. Many studies have been conducted to investigate the effect of LP on parts produced using additive manufacturing. The results showed that applying such a unique treatment can significantly enhance the overall performance of the part. In LP processes, the surface of the part is re-melted by the laser, resulting in smaller peaks and shallower valleys, which enable the development of smoother surfaces with the help of gravity and surface tension. Precise selection of laser parameters is essential to achieve optimal enhancement in the surface finish, microstructure, and mechanical properties of the treated parts. This paper aims to compile state-of-the-art knowledge in LP of additively manufactured metals and presents the optimal process parameters experimentally and modeling using artificial machine learning. The effects of laser power, the number of laser re-melting passes, and scanning speed on the final surface roughness and mechanical properties are comprehensively discussed in this work.

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Section: Numerical Analysismentioning

confidence: 61%

Recent Advancements in Post Processing of Additively Manufactured Metals Using Laser Polishing

Ali

Almotari

Qattawi

2023

JMMP

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“…LP of metals is reported since the mid-2000s [ 5 , 6 ] and is considered by many industries as a conceivable alternative to the expensive and time-consuming standard polishing methods [ 2 ]. In recent times, LP has gained new interest as a way to improve the surface quality of samples produced by additive manufacturing (AM) [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Manco et al [ 7 ] and Annamaria et al [ 8 ] wrote two detailed reviews of this process for AM samples.…”

Section: Introductionmentioning

confidence: 99%

“…Manco et al [ 7 ] and Annamaria et al [ 8 ] wrote two detailed reviews of this process for AM samples. Moreover, the LP process was investigated on the most common materials printed using an AM process; Obeidi et al [ 9 ] on 316 L stainless, Li et al [ 10 ] on Ti6Al4V, Yung et al [ 11 ] on CoCr, and Richter et al [ 12 ] on Co-Cr-Mo Alloy, and Dadbakhsh et al [ 13 ] on Inconel 718. In contrast, tool steels such as H11 [ 15 ] or X38CrMoV5-1 [ 16 ] are much less investigated.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Process Parameters for the Laser Polishing of Hardened Tool Steel

2022

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In mold making, the mold surface roughness directly affects the surface roughness of the produced part. To achieve surface roughness below 0.8 μm, the cost of surface finish is high and time-consuming. One alternative to the different grinding and polishing steps is laser polishing (LP). This study investigates and models the LP of tool steel (X38CrMoV5-1-DIN 1.2343), typical for the mold industry, having an initial rough surface obtained by electrical discharge machining. The microstructures of the re-melted layer and heat-affected zone due to the LP process were also studied. Four parameters: the laser spot size, velocity, maximum melt pool temperature and overlapping were investigated via a design of experiments (DoE) approach, specifically a factorial design. The responses were line roughness (Ra), surface roughness (Sa), and waviness (Wa). The surface topography was measured before and after the LP process by white light profilometer or confocal microscopy. DoE results showed that the selected factors interact in a complex manner, including the interactions, and depend on the responses. The DoE analysis of the results revealed that the roughness is mainly affected by the velocity, temperature and overlap. Based on a first DoE model, an optimization of the parameters was performed and allowed to find optimum parameters for the LP of the rough samples. The optimum conditions to minimize the roughness are a spot size of 0.9 mm, a velocity of 50 mm/s, a temperature of 2080 °C and an overlap of 90%. By using these parameters, the roughness could be reduced by a factor of almost 8 from 3.8 µm to approximately 0.5 µm. Observations of the microstructure reveal that the re-melted layer consists of columnar grains of residual austenite. This can be explained by the carbon intake of the electro-machined surface that helps stabilize the austenitic phase.

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“…In the 3rd-5th Conference on Laser Polishing, LaP 2018-2022 (held in Fraunhofer ILT, Aachen, Germany), besides traditional vacuum furnace annealing, no other innovation method of tensile residual stress-relief annealing was reported pertaining to laser polishing of both tool steel and additively manufactured alloys. In the last five years, many scholars have engaged in laser polishing research [9,[18][19][20][21][22][23][24][25], but none have presented an innovative method of eliminating tensile residual stress.…”

Section: Introductionmentioning

confidence: 99%

Laser Polishing and Annealing Injection Mold Using Dual-Beam Laser System

Chen

Zhou

et al. 2022

Coatings

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One of the challenges regarding the application of laser polishing in injection mold manufacturing is to eliminate the tensile residual stress on a polished cavity surface without the extra expenses of an annealing vacuum furnace. This study aims to develop a fast laser annealing method using a dual-beam laser system by which a mold cavity can be laser-polished and then laser-annealed. Fourteen mold steel specimens were laser-polished by a dual-beam laser, resulting in a roughness reduction from the initial state, Sa 1.11 μm, to Sa 0.16 μm, a smoother surface finish. A numerical simulation of laser annealing using the current CW laser was implemented to optimize the laser annealing parameters to guide the experiment of CW laser annealing. XRD measurement results showed that the tensile residual stress dropped from an initial 638 MPa to 10 MPa in an annealing cycle time of 40 min at 750 °C; therefore, fatigue cracks or stress corrosion cracks (SCC) on the mold cavity will no longer occur. Confocal microscopy, X-ray diffraction, and scanning electron microscopy were used to obtain the microstructure and phase composition of the microstructures, demonstrate that laser polishing and laser annealing by a dual-beam laser is a fast and effortless technique which can be effectively employed in injection mold manufacturing.

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Finite element simulation and experimental study of single-laser track in laser polishing of Ti6Al4V

Cited by 7 publications

References 25 publications

Recent Advancements in Post Processing of Additively Manufactured Metals Using Laser Polishing

Recent Advancements in Post Processing of Additively Manufactured Metals Using Laser Polishing

Optimization of Process Parameters for the Laser Polishing of Hardened Tool Steel

Laser Polishing and Annealing Injection Mold Using Dual-Beam Laser System

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