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.

scholarly journals Microstructure and Tensile Properties of AlSi10Mg Alloy Manufactured by Multi-Laser Beam Selective Laser Melting (SLM)

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1337 ◽  
Author(s):  
Zhonghua Li ◽  
Zezhou Kuai ◽  
Peikang Bai ◽  
Yunfei Nie ◽  
Guang Fu ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Selective Laser Melting ◽  
High Efficiency ◽  
Grain Structure ◽  
Laser Forming ◽  
Laser Melting ◽  
Forming Process ◽  
Powder Bed ◽  
Moulding Process ◽  
Melt Pool

The multi-beam selective laser forming system is a new type of powder bed laser forming equipment that is different from single-laser selective laser melting (SLM) printers. It is a new generation for a metal powder material moulding process that has high efficiency, large size and batch manufacturing. It is a new development of a powder bed laser forming process trend. In this paper, the microstructure and tensile properties of both the multi-laser-formed AlSi10Mg isolated and overlap areas are studied to ensure that the parts can achieve perfect seamless splicing and to identify whether the parts in different regions have the same performance. It was discovered that as the number of scans increases, the depth and width of the melt pool and microscopic grain structure in the overlap zone increase. The preferential crystallite growth orientation reaches the (200) plane. A small amount of smooth surface appeared at the fracture of the overlap area of the two scans, the dimples were reduced and the structure became larger, resulting in a decrease in tensile properties.

The Effects of Laser and Mechanical Forming on the Hardness and Microstructural Layout of Commercially Pure Grade 2 Titanium Alloy Plates

2017 ◽  
Author(s):  
Kadephi V. Mjali ◽  
Annelize Els-Botes ◽  
Peter M. Mashinini
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Scanning Speed ◽  
Grain Structure ◽  
Laser Forming ◽  
Major Influence ◽  
Forming Process ◽  
Commercially Pure ◽  
Profound Influence ◽  
Pure Grade

This paper illustrates the effects of the laser and mechanical forming on the hardness and microstructural distribution in commercially pure grade 2 Titanium alloy plates. The two processes were used to bend commercially pure grade 2 Titanium alloy plates to a similar radius also investigate if the laser forming process could replace the mechanical forming process in the future. The results from both processes are discussed in relation to the mechanical properties of the material. Observations from hardness testing indicate that the laser forming process results in increased hardness in all the samples evaluated, and on the other hand, the mechanical forming process did not influence hardness on the samples evaluated. There was no change in microstructure as a result of the mechanical forming process while the laser forming process had a major influence on the overall microstructure in samples evaluated. The size of the grains became larger with increases in thermal gradient and heat flux, causing changes to the overall mechanical properties of the material. The thermal heat generated has a profound influence on the grain structure and the hardness of Titanium. It is evident that the higher the thermal energy the higher is the hardness, but this only applies up to a power of 2.5kW. Afterwards, there is a reduction in hardness and an increase in grain size. The cooling rate of the plates has been proved to play a significant role in the resulting microstructure of Titanium alloys. The scanning speed plays a role in maintaining the surface temperatures of laser formed Titanium plates resulting in changes to both hardness and the microstructure. An increase in heat results in grain growth affecting the hardness of Titanium.

Grain orientations and grain boundary networks of YBa2Cu3O7−δ films deposited by metalorganic and pulsed laser deposition on biaxially textured Ni–W substrates

2006 ◽  
Vol 21 (4) ◽  
pp. 923-934 ◽  
Author(s):  
D.M. Feldmann ◽  
T.G. Holesinger ◽  
C. Cantoni ◽  
R. Feenstra ◽  
N.A. Nelson ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Grain Structure ◽  
Ex Situ ◽  
Full Width ◽  
Out Of Plane ◽  
Grain Orientations ◽  
Processed Sample

We report a detailed study of the grain orientations and grain boundary (GB) networks in YBa2Cu3O7-δ (YBCO) films ∼0.8 μm thick grown by both the in situ pulsed laser deposition (PLD) process and the ex situ metalorganic deposition (MOD) process on rolling-assisted biaxially textured substrates (RABiTS). The PLD and MOD growth processes result in columnar and laminar YBCO grain structures, respectively. In the MOD-processed sample [full-width critical current density Jc(0 T, 77 K) = 3.4 MA/cm2], electron back-scatter diffraction (EBSD) revealed an improvement in both the in-plane and out-of-plane alignment of the YBCO relative to the template that resulted in a significant reduction of the total grain boundary misorientation angles. A YBCO grain structure observed above individual template grains was strongly correlated to larger out-of-plane tilts of the template grains. YBCO GBs meandered extensively about their corresponding template GBs and through the thickness of the film. In contrast, the PLD-processed film [full width Jc(0 T, 77 K) = 0.9 MA/cm2] exhibited nearly perfect epitaxy, replicating the template grain orientations. No GB meandering was observed in the PLD-processed film with EBSD. Direct transport measurement of the intra-grain Jc(0 T, 77 K) values of PLD and MOD-processed films on RABiTS revealed values up to 4.5 and 5.1 MA/cm2, respectively. As the intra-grain Jc values were similar, the significantly higher full-width Jc for the MOD-processed sample is believed to be due to the improved grain alignment and extensive GB meandering.

Investigation of Effect of Phase Transformations on Mechanical Behavior of AISI 1010 Steel in Laser Forming

2005 ◽  
Vol 129 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Yajun Fan ◽  
Zhishang Yang ◽  
Peng Cheng ◽  
Keith Egland ◽  
Lawrence Yao
Keyword(s):  
Phase Transformation ◽  
Phase Transformations ◽  
Volume Fraction ◽  
Constitutive Relationship ◽  
Laser Forming ◽  
Transformation Kinetic ◽  
Forming Process ◽  
Element Analysis ◽  
Relationship Of ◽  
Phase Transformation Kinetic

In laser forming, phase transformations in the heat affected zone take place under steep cooling rates and temperature gradients, and have a significant affect on the laser forming process and final mechanical properties of products. In this work, phase transformations during laser forming of AISI 1010 steel are experimentally and numerically investigated and the transient volume fraction of each available phase is calculated by coupling the thermal history from finite element analysis with a phase transformation kinetic model. Consequently, the flow stresses of material are obtained from the constitutive relationship of the phases, and the laser forming process is modeled considering the effect of work hardening, recrystallization and phase transformation. A series of carefully controlled experiments are also conducted to validate the theoretically predicted results.

Temperature Monitoring during Laser Beam Forming of Steel Sheets

2014 ◽  
Vol 622-623 ◽  
pp. 811-818
Author(s):  
Stephen Akinlabi ◽  
Esther Titilayo Akinlabi
Keyword(s):  
Laser Beam ◽  
Temperature Monitoring ◽  
Laser Forming ◽  
Great Promise ◽  
Beam Forming ◽  
Measured Temperature ◽  
Data Logger ◽  
Forming Process ◽  
Line Energy ◽  
Steel Sheets

Laser Beam Forming is a flexible manufacturing process with great promise for sheet and metal forming, hence, considered as a novel manufacturing method for forming and shaping of metallic components. Being a thermo-mechanical forming process that enables parts or components to be formed with external heat of a laser beam, it is important to monitor and measure the temperature during the laser forming process in order to ensure the integrity of the processed components. This study reports on the temperature monitoring and measurement during laser beam forming process of steel sheets. The experimental design followed the L-27 Taguchi Orthogonal Array. The temperature of nine sets of samples laser beamed formed at different process parameters were monitored using the thermocouple data logger. The temperature for all the components formed at the nine parameter windows were analysed during the process. Hence, it was observed that the measured temperature increases with the increasing line energy during the laser beam forming process.

An Analytical Study on Laser Forming Process of Sheet Metals, Using New Elasto-Plastic Temperature Dependent Material Model

2012 ◽  
Vol 622-623 ◽  
pp. 569-574 ◽  
Author(s):  
Shams Torabnia ◽  
Afshin Banazadeh
Keyword(s):  
Laser Beam ◽  
Sheet Metal ◽  
Analytical Model ◽  
Plastic Material ◽  
Material Model ◽  
Laser Forming ◽  
Sheet Metals ◽  
Temperature Dependent ◽  
Forming Process ◽  
Heated Zone

The laser forming process is one of the last technologies on forming of sheet metals with laser beam heat distribution. In this process laser beam moves across the top surface of the sheet metal and the heated zone expands and causes a great moment that deforms the sheet metal. Subsequently, the heated zone gets cooled and provides a reverse strain and moment. The final bending angle is a combination of two phases. Due to the complexity of the process, it is studied with different approaches; FEM analysis and analytical as well as empirical methods. The laser forming is a sensible process regarding the material properties. Also, because of the temperature change during the process, it is important to use a temperature dependent model. In this study The FEM model is proposed for simulation of the mechanism. Based on the simulation results, an integrated analytical model is then developed by a new elasto-plastic material model considering linear strain hardening, combined with the temperature dependent mechanical and physical properties. In addition, the temperature dependent tangential modulus is used instead of the yield point of the material to improve accuracy in the plastic deformation phase. Finally, the analytical model is compared with the FEM standard code, which showed a great conformity.

scholarly journals Study on strong spinning preparation method and mechanism of the industrial pure titanium ultrafine crystallization

2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
Pure Titanium ◽  
Grain Structure ◽  
Theoretical Research ◽  
Ultrafine Grain ◽  
Forming Process ◽  
Spinning Process ◽  
And Performance ◽  
Material Utilization

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.

scholarly journals Study on a New Forming Method—Thread Rolling by Crystal Plasticity Finite Element Simulation

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 503
Author(s):  
Yuheng Zhang ◽  
Zhiqing Hu ◽  
Liming Guo
Keyword(s):  
Finite Element ◽  
Crystal Plasticity ◽  
Strain Curve ◽  
Forming Process ◽  
Crystal Plasticity Finite Element ◽  
Pole Figures ◽  
Grain Orientations ◽  
Thread Rolling ◽  
Polycrystalline Model ◽  
High Consistency

In order to study a new thread rolling forming process from a microscopic perspective, a polycrystalline model was established, based on the crystal plasticity finite element method (CPFEM) and Voronoi polyhedron theory. The fluidity of metals was studied to explain the reason for the concave center. The simulation results show that the strain curve of the representative element can more truly reflect the deformation behavior of the material. The grain orientations after deformation are distributed near the initial orientation. The evolution of each slip system is determined by the initial grain orientations and grain locations. The pole figures obtained from the experiment show high consistency with the pole figures obtained by simulation, which verifies the accuracy of the texture prediction by CPFEM. The experimental results show that thread rolling is more uniform in deformation than ordinary rolling.

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