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).

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 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.

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.

Research of Process Parameters of Screwy Thin-Walled Part with Coaxial Inside-Beam Powder Feeding Accumulation

2014 ◽  
Vol 528 ◽  
pp. 185-190
Author(s):  
Yu Liu ◽  
Ge Yan Fu ◽  
Shi Hong Shi ◽  
Ming Jun Wu
Keyword(s):  
Laser Cladding ◽  
Process Parameters ◽  
Wall Thickness ◽  
Manufacturing Process ◽  
Laser Scanning ◽  
Continuous Laser ◽  
Forming Process ◽  
Scanning Path ◽  
Thin Walled ◽  
Powder Feeding

Based on the technology of laser cladding manufacturing process with coaxial inside-beam powder feeding, screwy thin-walled part is accumulated on the substrate of 45# steel by controlling the angle of inclination, scanning paths, Z axis incremental and power. Through the inclined wall accumulation model and a large number of tests, limiting angle of the cladding accumulation is obtained. According to the forming process of screwy thin-walled part, two scanning paths are designed, which include continuous laser scanning between each layer and intermittent laser scanning between each layer, the better scanning path is gained by analyzing each path. A good forming part is obtained by controlling Z axis incremental and power simultaneously. The forming part is higher with smooth appearance and lower roughness, and wall thickness is uniformed.

scholarly journals Artificial neural network for modeling and investigating the effects of forming tool characteristics on the accuracy and formability of thin aluminum alloy blanks when using SPIF

2021 ◽  
Author(s):  
Sherwan Mohammed Najm ◽  
Imre Paniti
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Process Parameters ◽  
Single Point ◽  
Tool Material ◽  
Deformation Mode ◽  
Geometric Accuracy ◽  
Forming Process ◽  
Tool Shape ◽  
Artificial Neural

AbstractIncremental Sheet Forming (ISF) has attracted attention due to its flexibility as far as its forming process and complexity in the deformation mode are concerned. Single Point Incremental Forming (SPIF) is one of the major types of ISF, which also constitutes the simplest type of ISF. If sufficient quality and accuracy without defects are desired, for the production of an ISF component, optimal parameters of the ISF process should be selected. In order to do that, an initial prediction of formability and geometric accuracy helps researchers select proper parameters when forming components using SPIF. In this process, selected parameters are tool materials and shapes. As evidenced by earlier studies, multiple forming tests with different process parameters have been conducted to experimentally explore such parameters when using SPIF. With regard to the range of these parameters, in the scope of this study, the influence of tool material, tool shape, tool-end corner radius, and tool surface roughness (Ra/Rz) were investigated experimentally on SPIF components: the studied factors include the formability and geometric accuracy of formed parts. In order to produce a well-established study, an appropriate modeling tool was needed. To this end, with the help of adopting the data collected from 108 components formed with the help of SPIF, Artificial Neural Network (ANN) was used to explore and determine proper materials and the geometry of forming tools: thus, ANN was applied to predict the formability and geometric accuracy as output. Process parameters were used as input data for the created ANN relying on actual values obtained from experimental components. In addition, an analytical equation was generated for each output based on the extracted weight and bias of the best network prediction. Compared to the experimental approach, analytical equations enable the researcher to estimate parameter values within a relatively short time and in a practicable way. Also, an estimate of Relative Importance (RI) of SPIF parameters (generated with the help of the partitioning weight method) concerning the expected output is also presented in the study. One of the key findings is that tool characteristics play an essential role in all predictions and fundamentally impact the final products.

Microstructure Integrated Modeling of Multiscan Laser Forming

2002 ◽  
Vol 124 (2) ◽  
pp. 379-388 ◽  
Author(s):  
Jin Cheng ◽  
Y. Lawrence Yao
Keyword(s):  
Flow Stress ◽  
Numerical Models ◽  
Flow Behavior ◽  
Fem Simulation ◽  
Constitutive Models ◽  
Low Carbon Steel ◽  
Laser Forming ◽  
Low Carbon ◽  
Forming Process ◽  
Heating And Cooling

Laser forming of steel is a hot forming process with high heating and cooling rate, during which strain hardening, dynamic recrystallization, and phase transformation take place. Numerical models considering strain rate and temperature effects only usually give unsatisfactory results when applied to multiscan laser forming operations. This is mainly due to the inadequate constitutive models employed to describe the hot flow behavior. In this work, this limitation is overcome by considering the effects of microstructure change on the flow stress in laser forming processes of low carbon steel. The incorporation of such flow stress models with thermal mechanical FEM simulation increases numerical model accuracy in predicting geometry change and mechanical properties.

Affected Characteristics Analysis of the Pulsed Laser Forming of Metal Sheet

2008 ◽  
Vol 375-376 ◽  
pp. 333-337
Author(s):  
Li Jun Yang ◽  
Yang Wang
Keyword(s):  
Laser Beam ◽  
Pulsed Laser ◽  
Metal Sheet ◽  
Grain Structure ◽  
Experimental Result ◽  
Laser Forming ◽  
Forming Process ◽  
Grain Orientations ◽  
Characteristics Analysis ◽  
Relationship Of

Laser forming of metal sheet is a forming technology of sheet without a die that the sheet is deformed by internal thermal stress induced by partially irradiation of a laser beam. In this paper, the bending behavior of common stainless steel 1Cr18Ni9 sheet is studied after being irradiated by straight line with a Nd:YAG pulsed laser beam. The aim of the investigation is to find out the relationship of the physical behaviors of heat affected zone (HAZ) with the pulse parameters of the laser. Through the analysis of the fundamental theory of pulsed laser affected, this paper shows the affected characteristics of metal sheet with pulsed laser forming. The results show that the microstructure of HAZ of pulsed laser scanned is layered, and the micro-hardness is improved than that in matrix. The microstructures show that the deformed grain structure is inhomogeneous, that caused the grain sizes and grain orientations in HAZ to become different. By qualitative analysis of experimental result, the conclusion obtained may provide basis for theoretical investigation and possible industrial application of laser forming process in the future.

Laser forming of a bowl shaped surface with a stationary laser beam

2016 ◽  
Vol 77 ◽  
pp. 126-136 ◽  
Author(s):  
Shitanshu Shekhar Chakraborty ◽  
Harshit More ◽  
Ashish Kumar Nath
Keyword(s):  
Laser Beam ◽  
Laser Forming ◽  
Shaped Surface
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