Modeling of laser heat source considering light scattering during laser transmission welding

Liu, Huixia; Liu, Wei; Zhong, Xuejiao; Liu, Baoguang; Guo, Dehui; Wang, Xiao

doi:10.1016/j.matdes.2016.03.052

Cited by 19 publications

(12 citation statements)

References 38 publications

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“…The quenching temperature of high boron alloy steel is 1050 °C, at which secondary borocarbides are partially dissolved in the matrix, and eutectic borocarbides are easy to fracture and be spheroidized, leading to the improvement of impact toughness of high boron alloy steel . The microstructures of high‐boron high speed steel roll spray cooling quenching from 1050 °C and spray cooling quenching from 1050 °C + tempering from 525 °C are shown in Figures and .…”

Section: Resultsmentioning

confidence: 99%

A study of centrifugal cast high boron high speed steel

Qihong

Jiao

et al. 2014

Materialwissenschaft Werkst

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In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.

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Section: Resultsmentioning

confidence: 99%

A study of centrifugal cast high boron high speed steel

Qihong

Jiao

et al. 2014

Materialwissenschaft Werkst

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“…As previously discussed, the morphology depends upon the type of nucleating agents or the compounding ingredients used in the formulation and the processing conditions. Hence, for LT parts, the scattering coefficient plays an important role [ 222 ]. It is not desirable to have higher scattering for a good weld seam quality.…”

Section: Performance Characterisation and Weld Qualitymentioning

confidence: 99%

Laser Transmission Welding of Semi-Crystalline Polymers and Their Composites: A Critical Review

et al. 2021

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The present review provides an overview of the current status and future perspectives of one of the smart manufacturing techniques of Industry 4.0, laser transmission welding (LTW) of semi-crystalline (SC) polymers and their composites. It is one of the most versatile techniques used to join polymeric components with varying thickness and configuration using a laser source. This article focuses on various parameters and phenomena such as inter-diffusion and microstructural changes that occur due to the laser interaction with SC polymers (specifically polypropylene). The effect of carbon black (size, shape, structure, thermal conductivity, dispersion, distribution, etc.) in the laser absorptive part and nucleating agent in the laser transmissive part and its processing conditions impacting the weld strength is discussed in detail. Among the laser parameters, laser power, scanning speed and clamping pressure are considered to be the most critical. This review also highlights innovative ideas such as incorporating metal as an absorber in the laser absorptive part, hybrid carbon black, dual clamping device, and an increasing number of scans and patterns. Finally, there is presented an overview of the essential characterisation techniques that help to determine the weld quality. This review demonstrates that LTW has excellent potential in polymer joining applications and the challenges including the cost-effectiveness, innovative ideas to provide state-of-the-art design and fabrication of complex products in a wide range of applications. This work will be of keen interest to other researchers and practitioners who are involved in the welding of polymers.

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“…where a = ln(A) − µ 2 / (2σ 2 ), b = µ/σ 2 and c = −1/ (2σ 2 ). Accordingly, the unknowns become a, b and c in the linear equation (2) instead of A, µ and σ in the nonlinear equation (1). Next, if the observations y are noisy, then they can be modeled asŷ = y + w; each contains the ideal data point, y, that is corrupted by the noise, w with SD of σ w .…”

Section: Caruana's Algorithmmentioning

confidence: 99%

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confidence: 99%

A Fast, Accurate, and Separable Method for Fitting a Gaussian Function [Tips & Tricks]

Al-Nahhal

Dobre

Başar

et al. 2019

IEEE Signal Process. Mag.

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The Gaussian function (GF) is widely used to explain the behavior or statistical distribution of many natural phenomena as well as industrial processes in different disciplines of engineering and applied science. For example, the GF can be used to model an approximation of the Airy disk in image processing, laser heat source in laser transmission welding [1], practical microscopic applications [2], and fluorescence dispersion in flow cytometric DNA histograms [3]. In applied sciences, the noise that corrupts the signal can be modeled by the Gaussian distribution according to the central limit theorem. Thus, by fitting the GF, the corresponding process/phenomena behavior can be well interpreted.This article introduces a novel fast, accurate, and separable algorithm for estimating the GF parameters to fit observed data points. A simple mathematical trick can be used to calculate the area under the GF in two different ways. Then, by equating these two areas, the GF parameters can be easily obtained from the observed data. GAUSSIAN FUNCTION FITTING APPROACHESA GF has a symmetrical bell-shape around its center, with a width that smoothly decreases as it moves away from its center on the x-axis. The mathematical form of the GF iswith three shape-controlling parameters, A, µ and σ, where A is the maximum height (amplitude) that can be achieved on the y-axis, µ is the curve-center (mean) on the x-axis, and σ is the standard deviation (SD) which controls the width of the curve along the x-axis. The aim of this article is to present a new method for the accurate estimation of these three parameters. The difficulty of this lies in estimating the three shape-controlling parameters (A, µ and σ) from observations, that are generally noisy, by solving an overdetermined nonlinear system of equations. The standard solutions for fitting the GF parameters from noisy observed data are obtained by one of the following two approaches:1) Solving the problem as a nonlinear system of equations using one of the leastsquares optimization algorithms. This solution employs an iterative procedure such 2 as the Newton-Raphson algorithm [4]. The drawbacks of this approach are the iterative procedure, which may not converge to the true solution, as well as its high cost from the computational complexity perspective. 2) Solving the problem as a linear system of equations based on the fact that the GF is an exponential of a quadratic function. By taking the natural logarithm of the observed data, the problem can be solved in polynomial time as a 3 × 3 linear system of equations. Two traditional algorithms have been proposed in this context: Caruana's algorithm [5] and Guo's algorithm [6]. Furthermore, instead of taking the natural logarithm, the partial derivative is used in Roonizi's algorithm [7].In this article, we will consider only the second approach, which is more suitable for most scientific applications, due to its simplicity and avoidance of the drawbacks of the first approach. Let us start with a brief introduction of the existing three...

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Modeling of laser heat source considering light scattering during laser transmission welding

Cited by 19 publications

References 38 publications

A study of centrifugal cast high boron high speed steel

A study of centrifugal cast high boron high speed steel

Laser Transmission Welding of Semi-Crystalline Polymers and Their Composites: A Critical Review

A Fast, Accurate, and Separable Method for Fitting a Gaussian Function [Tips & Tricks]

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