Predictive modeling of multi-track laser hardening of AISI 4140 steel

Lakhkar, Ritesh S.; Shin, Yung C.; Krane, Matthew John M.

doi:10.1016/j.msea.2007.07.054

Cited by 133 publications

(51 citation statements)

References 17 publications

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“…The enabler to enhance all of these factors is the temperature field [14] that is caused by the intensity distribution of the laser as well as the feed rate, spot size and temperature regulation. A lot of research has been done to predict the outcome of these parameters by simulation [12,[15][16][17]. Kunc et al [18], for example, predicted multitrack hardening of the investigated 42CrMo4 (AISI 4140).…”

Section: Introductionmentioning

confidence: 99%

Optimization of the Laser Hardening Process by Adapting the Intensity Distribution to Generate a Top-hat Temperature Distribution Using Freeform Optics

2017

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Laser hardening is a surface hardening process which enables high quality results due to the controllability of the energy input. The hardened area is determined by the heat distribution caused by the intensity profile of the laser beam. However, commonly used top-hat laser beams do not provide an ideal temperature profile. Therefore, in this paper the beam profile, and thus the temperature profile, is optimized using freeform optics. The intensity distribution is modified to generate a top-hat temperature profile on the surface. The results of laser hardening with the optimized distribution are thereupon compared with results using a top-hat intensity distribution.

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Section: Introductionmentioning

confidence: 99%

Optimization of the Laser Hardening Process by Adapting the Intensity Distribution to Generate a Top-hat Temperature Distribution Using Freeform Optics

2017

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“…However, these processes, while having many advantages, are often expensive, time consuming, and do not allow a selective treatment of small portions of the component. In this respect, the use of lasers for the thermal surface treatment of steel components has appeared as an innovative solution since it offers selectivity, leaving areas not directly exposed to laser radiation unaltered, making process control very easy and facilitating manipulation [7][8][9][10]. A high power laser beam may be directed onto a surface using very precise multi-axis handling systems.…”

Section: Introductionmentioning

confidence: 99%

“…Every laser track re-heats the area previously heated, inducing a transformation of the martensite into tempered martensite characterized by lower hardness. Thus, the back tempering phenomena leads to a lack of uniformity of the surface mechanical properties [8,18]. A High Power Diode Laser (HPDL), different from other sources, is well suited to surface hardening.…”

Section: Introductionmentioning

confidence: 99%

High Power Diode Laser (HPDL) for Fatigue Life Improvement of Steel: Numerical Modelling

Guarino

Ponticelli

2017

Metals

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This paper deals with the improvement of fatigue life of AISI 1040 steel components by using a High Power Diode Laser (HPDL). First, the meaningfulness of each operational parameter was assessed by varying the experimental laser power and scan speed. After laser treatment, fatigue tests were performed to investigate the influence of laser processing parameters on the material resistance. The fatigue tests were carried out by using a rotating bending machine. Wöhler curves were obtained from the analysis of experimental results. Second, in the light of experimental findings, a 3D transient finite element method for a laser heat source, with Gaussian energy distribution, was developed to predict the temperature and the depth of the heat affected zone on the workpiece. The model allows us to understand the relationship between the laser treatment parameters and the fatigue enhancement of the components. HPDL was found to significantly increase the fatigue life of the irradiated workpieces, thus revealing its suitability for industrial applications.

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“…More detailed research has also been performed on defining the effect of process parameters on phase transformation during the heat treatment of materials. [10][11][12] Obviously, reaching a specific microstructure or hardness level in the buildup requires understanding of the temperaturephase transformation relation.…”

Section: Introductionmentioning

confidence: 99%

“…The minimum required cooling rate for transforming austenite to martensite for AISI 4140 is about 25°C/s. [13] On the other side, the cooling rate in the LPD process is usually much higher than 25°C/s (on the order of 10 4°C /s [11] ) because of a relatively large cold substrate. Therefore, the austenite by crossing the martensite start temperature (M s ) transforms to martensite until it reaches the martensite end temperature (M f ).…”

Section: Introductionmentioning

confidence: 99%

Thermokinetic Modeling of Phase Transformation in the Laser Powder Deposition Process

Foroozmehr

Kovacevic

2009

Metall Mater Trans A

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A finite element model coupled with a thermokinetic model is developed to predict the phase transformation of the laser deposition of AISI 4140 on a substrate with the same material. Four different deposition patterns, long-bead, short-bead, spiral-in, and spiral-out, are used to cover a similar area. Using a finite element model, the temperature history of the laser powder deposition (LPD) process is determined. The martensite transformation as well as martensite tempering is considered to calculate the final fraction of martensite, ferrite, cementite, e-carbide, and retained austenite. Comparing the surface hardness topography of different patterns reveals that path planning is a critical parameter in laser surface modification. The predicted results are in a close agreement with the experimental results.

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Predictive modeling of multi-track laser hardening of AISI 4140 steel

Cited by 133 publications

References 17 publications

Optimization of the Laser Hardening Process by Adapting the Intensity Distribution to Generate a Top-hat Temperature Distribution Using Freeform Optics

Optimization of the Laser Hardening Process by Adapting the Intensity Distribution to Generate a Top-hat Temperature Distribution Using Freeform Optics

High Power Diode Laser (HPDL) for Fatigue Life Improvement of Steel: Numerical Modelling

Thermokinetic Modeling of Phase Transformation in the Laser Powder Deposition Process

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