scholarly journals Hardening in laser forming under the temperature gradient mechanism

2021 ◽  
Vol 1135 (1) ◽  
pp. 012006
Author(s):  
Georgi Nikolaev Nikolov ◽  
Anders Noel Thomsen ◽  
Morten Kristiansen
Keyword(s):  
Process Parameters ◽  
Hardness Test ◽  
Processing Parameters ◽  
304 Stainless Steel ◽  
Laser Forming ◽  
Hardness Distribution ◽  
Theoretical Discussion ◽  
Forming Process ◽  
Bottom Side ◽  
The Relationship

Abstract Laser forming is a contactless thermal forming process that can be applied for both single and double-curved geometries. When it comes to prototyping and small batch production, laser forming has the potential to compete with conventional sheet-metal forming processes; however, an investigation of the relationship between process parameters, hardness distribution and the bend rate is lacking. This study examines the influence of using different sets of processing parameters on the bend rate and the hardness distribution. ANSI 304 stainless steel samples of 1 and 3 mm thickness are laser formed up to 90° with a bend radius equal to their thickness. A theoretical discussion of the material’s hardening kinetics is used to generalize the results. Micro-Vickers hardness test is used to measure the hardness distribution along the 3 mm samples to support the theoretical discussion. The results show that the bend rate increases when using different sets of process parameters; furthermore, the bend arc length has shown to have a significant influence over the bend rate. An increase of hardness is observed on the bottom side of the laser formed samples, indicating potential strain hardening.

Prediction and Optimization of Deformations in Coupling Mechanism Based Laser Forming of Sheet Metals

2019 ◽  
Vol 969 ◽  
pp. 552-557
Author(s):  
Kuntal Maji
Keyword(s):  
Process Parameters ◽  
Metal Forming ◽  
Three Dimensional ◽  
Laser Forming ◽  
Coupling Mechanism ◽  
Sheet Metals ◽  
Forming Process ◽  
Out Of Plane ◽  
Metal Forming Process ◽  
Plane Deformations

Fabricating three dimensional shaped surfaces from flat sheet metals by laser forming, both out-of-plane and in-plane deformations are required. This article presents the modeling of coupling mechanism activated laser forming of sheet metals based on experimental data for prediction and optimization of bending and thickening deformations. Experiments were performed based on a central composite design of experiments on coupling mechanism based laser metal forming process considering the input process parameters like laser power, scan speed and spot diameter, bending and thickening were taken as the outputs. Neural network and neuro-fuzzy system-based models were developed to carry out both forward and inverse modeling of the laser metal forming process under the coupling mechanism. Multi-objective optimization based on the non-dominated sorting genetic algorithm was used to obtain multiple optimal solutions to achieve different amounts of out-of-plane and in-plane deformations. The proposed method could guide for a suitable selection of the process parameters to produce three-dimensional shapes utilizing coupling mechanism-based laser forming using multiple laser line heating.

Mechanics Study on Leveling Process by a Roller during Selective Laser Forming

2013 ◽  
Vol 670 ◽  
pp. 101-105 ◽  
Author(s):  
Jin Hui Liu ◽  
W.J. Xie ◽  
C. Zhao ◽  
L. Zhang ◽  
Z.L. Lu
Keyword(s):  
Process Parameters ◽  
Influence Factor ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Laser Forming ◽  
Powder Materials ◽  
Forming Process ◽  
Forming Quality ◽  
Common Reference ◽  
Model Of Friction

Generally, pressures resulted from roller during leveling process in selective laser sintering has the effect of densification of powder materials. But extra frictions due to them become the forces which always deteriorate the surface of the part and mark it with several lines trace. Sometimes, the manufacturing can even not continue if these forces accumulate to a large extent to move the whole part. Therefore, the whole forming process will be obliged to stop owing to the displacement of part from above mentioned damage. In this work, the emerging reason and related variation factors of these forces were studied mathematically, the mathematical and physical model of friction force was also built to describe the connections between the leveling process parameters and them. How to control the influence factor of friction to abate their damages to surfaces and promote the forming quality were also discussed based on these models. This will provide a common reference for the application of selective laser sintering technology.

scholarly journals Trajectory Prediction of Three Dimensional Forming Tube Based On Kalman Filter

2021 ◽  
Author(s):  
Jianjun Wu ◽  
Liang Bo ◽  
Junzhou Yang
Keyword(s):  
Kalman Filter ◽  
Spline Interpolation ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Trajectory Prediction ◽  
Forming Process ◽  
Variable Curvature ◽  
Relevant Calculation ◽  
The Relationship ◽  
Initial Process

Abstract This article focuses on the prediction of forming trajectory and process optimization during the forming process for the variable curvature tubes. Firstly, through cubic B-spline interpolation, the geometric characteristics of the axis of the target tube are obtained. An overall tube is "separated and then integrated", and the relationship between geometric parameters and processing parameters is established to obtain the initial process parameters. Based on the Extended Kalman Filter (EKF) algorithm, the motion model and observation model of tube forming using simulation are presented section by section, and the relevant calculation and analysis are carried out. The forming trajectory has been predicted and the processing parameters are optimized during the processing process, in which the effectiveness of the processing optimum scheme is illustrated.

Parameter optimization of aluminum alloy thin structures obtained by Selective Laser Melting

MRS Advances ◽  
2019 ◽  
Vol 4 (55-56) ◽  
pp. 2997-3005
Author(s):  
Malena Ley Bun Leal ◽  
Barbara Bermudez-Reyes ◽  
Patricia del Carmen Zambrano Robledo ◽  
Omar Lopez-Botello
Keyword(s):  
Selective Laser Melting ◽  
Process Parameters ◽  
Orthogonal Design ◽  
Processing Parameters ◽  
Future Research ◽  
Laser Melting ◽  
Complex Process ◽  
The Relationship ◽  
Fabrication Parameters

ABSTRACTSelective Laser Melting (SLM) involves numerous fabrication parameters, the interaction between those parameters determine the final characteristics of the resulting part and because of the latter, it is considered a complex process. Low-density components is one of the main issues of the SLM process, due to the incorrect selection of process parameters. These defects are undesired in high specialized applications (i.e. aerospace, aeronautic and medical industries). Therefore, the characterization of the defects (pores) found in aluminum parts manufacture by SLM and the relationship with fabrication parameters was performed. A robust orthogonal design of experiments was implemented to determine process parameters, and then parts were manufactured in SLM. Relative density of the samples was then characterized using the Archimedes principle and microscopy; the data was then statistically analyzed in order to determine the optimal process parameters. The main purpose of the present research was to establish the best processing parameters of an in-house SLM system, as well as to characterize the pore geometry in order to fully eliminate pores in a future research.

Investigation of Deformation Induced Martensitic Transformation during Incremental Forming of 304 Stainless Steel Wires

2015 ◽  
Vol 651-653 ◽  
pp. 645-650 ◽  
Author(s):  
Bernd Kuhfuss ◽  
Eric Moumi ◽  
Brigitte Clausen ◽  
Jeremy Epp ◽  
Bernd Koehler
Keyword(s):  
Volume Fraction ◽  
Processing Parameters ◽  
304 Stainless Steel ◽  
Strain Rates ◽  
X Ray Diffraction ◽  
Forming Process ◽  
Cold Forming ◽  
X Ray ◽  
Steel Wires ◽  
Different Temperatures

Wires with 1 mm initial diameter have been reduced between 10 and 64 percent at different temperatures and strain rates by infeed rotary swaging, which is an incremental cold forming process mainly used for rods and pipes. The volume fraction of martensite in the deformed wires has been determined by X-Ray diffraction and by magnetic induction for different processing parameters. Measurements show that for already small percentage of reduction, martensite is present in the wires and its amount changes with the strain rate and temperature. While for smaller strain rates at room temperature the formation of martensite is promoted, it is restrained for higher strain rates and higher temperatures. Results also reveal that the martensite distribution in the sample is inhomogeneous. Further investigations have been made to analyze the microstructure by optical microscopy and to determine mechanical properties by tensile testing.

Role of process parameters during additive manufacturing by direct metal deposition of Inconel 718

2017 ◽  
Vol 23 (5) ◽  
pp. 919-929 ◽  
Author(s):  
Bo Chen ◽  
Jyoti Mazumder
Keyword(s):  
Additive Manufacturing ◽  
Cooling Rate ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Inconel 718 ◽  
Processing Parameters ◽  
Forming Quality ◽  
Content Type ◽  
Forming Characteristics ◽  
The Relationship

Purpose The aim of this research is to study the influence of laser additive manufacturing process parameters on the deposit formation characteristics of Inconel 718 superalloy, the main parameters that influence the forming characteristics, the cooling rate and the microstructure were studied. Design/methodology/approach Orthogonal experiment design method was used to obtain different deposit shape and microstructure using different process parameters by multiple layers deposition. The relationship between the processing parameters and the geometry of the cladding was analyzed, and the dominant parameters that influenced the cladding width and height were identified. The cooling rates of different forming conditions were obtained by the secondary dendrite arm spacing (SDAS). Findings The microstructure showed different characteristics at different parts of the deposit. Cooling rate of different samples were obtained and compared by using the SDAS, and the influence of the process parameters to the cooling rate was analyzed. Finally, micro-hardness tests were done, and the results were found to be in accordance with the micro-structure distribution. Originality/value Relationships between processing parameters and the forming characteristics and the cooling rates were obtained. The results obtained in this paper will help to understand the relationship between the process parameters and the forming quality of the additive manufacturing process, so as to obtain the desired forming quality by appropriate parameters.

scholarly journals Fabrication of Saddle-Shaped Surfaces by a Laser Forming Process: An Experimental and Statistical Investigation

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 883 ◽  
Author(s):  
Mehdi Safari ◽  
Ricardo Alves de Sousa ◽  
Jalal Joudaki
Keyword(s):  
Process Parameters ◽  
Main Idea ◽  
Movement Pattern ◽  
Statistical Investigation ◽  
Laser Forming ◽  
Forming Process ◽  
Shaped Surface ◽  
Pattern Movement ◽  
Scanning Path ◽  
Input Variables

Laser forming is a powerful tool for fabricating complicated shapes economically. The pattern of laser movement (irradiating scheme) has an essential effect on the shaped form. In this article, the forming of a saddle-shaped surface will be investigated experimentally by the laser forming process. A spiral irradiating scheme is implemented to manufacture a saddle-shaped surface. The main idea of this study is the investigation of the simultaneous variations of the process parameters and their effect on the curvature of the final part. The process parameters of the study are the spiral pitch, number of spiral passes, and movement pattern (In-to-Out or reversely Out-to-In scanning path). The response surface methodology is selected for experimentation. The measurement of the deformation results shows that the deformations of laser-formed saddle-shaped surfaces decrease with an increase in the spiral pitch of the path. Additionally, the deformations of the saddle-shaped surface increase by increasing the number of spiral passes. The results demonstrate that the pattern movement has little effect on the deformations of laser-formed saddle-shaped surfaces and an Out-to-In spiral pattern movement is advised. At last, the proper input variables to obtain the maximum value of displacements for the saddle point are determined (10 mm spiral pitch, three spiral passes, and Out-to-In pattern movement).

scholarly journals Recent Advances in the Laser Forming Process: A Review

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1472
Author(s):  
Mehdi Safari ◽  
Ricardo Alves de Sousa ◽  
Jalal Joudaki
Keyword(s):  
Process Parameters ◽  
Optimization Technique ◽  
Laser Forming ◽  
Forming Process ◽  
Laser Bending ◽  
Heating Source ◽  
Fiber Metal ◽  
Local Softening ◽  
Doubly Curved ◽  
And Control

Laser forming is an emerging manufacturing process capable of producing either uncomplicated and complicated shapes by employing a concentrated heating source. The heat source movement creates local softening, and a plastic strain will be induced during the rise of temperature and the subsequent cooling. This contactless forming process may be used for the simple bending of sheets and tubes or fabrication of doubly-curved parts. Different studies have been carried out over recent years to understand the mechanism of forming and predicting the bending angle. The analysis of process parameters and search for optimized manufacturing conditions are among the most discussed topics. This review describes the main recent findings in the laser forming of single and multilayer sheets, composite and fiber-metal laminate plates, force assisted laser bending, tube bending by laser beam, the optimization technique implemented for process parameters selection and control, doubly-curved parts, and the analytical solutions in laser bending. The main focus is set to the researches published since 2015.

Quantify the Weld Line and its Optimization Based on the Taguchi and the Moldflow Secondary Development

2013 ◽  
Vol 444-445 ◽  
pp. 1021-1025
Author(s):  
Zhi Shan ◽  
Shu Hao Qin ◽  
Liang Qiang Wei
Keyword(s):  
Experimental Data ◽  
Process Parameters ◽  
Process Design ◽  
Weld Line ◽  
Secondary Development ◽  
Orthogonal Experimental Design ◽  
Forming Process ◽  
The Impact ◽  
The Relationship ◽  
Important Basis

Designed the weld line quantization algorithm based on the moldflow secondary development of technology, obtained the numerical experimental data of weld line with this. Analyzed of the impact of the relationship between the process parameters and weld line, and optimized the process parameters by orthogonal experimental design. These provided an important basis for the forming process design.

Study on Fiber Laser Single Melting Track During Selective Laser Forming

2010 ◽  
Vol 97-101 ◽  
pp. 4020-4023
Author(s):  
Jin Hui Liu ◽  
Rui Di Li ◽  
Can Zhao
Keyword(s):  
Selective Laser Melting ◽  
Research Result ◽  
Processing Parameters ◽  
Laser Forming ◽  
Powder Materials ◽  
Laser Melting ◽  
Metal Component ◽  
The Relationship ◽  
Thermal Physical Properties

Melting tracks with and without powder materials were studied by varying the parameters in selective laser melting. Several characters of melting track such as melting width and gilled state stripes were analyzed combining the relationship between the powder materials and processing parameters. Connected with balling effects, thermal transmission and thermal physical properties of powder materials, the formation of above character were explained. The research result of this work would provide a basic foundation for the further investigation of the quality of end metal component manufactured by selective laser melting method.

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