Quality Assessment and Metallurgical Examination of Laser Welded Sheets

2009 ◽  
Vol 83-86 ◽  
pp. 611-615
Author(s):  
Numan Abu-Dheir ◽  
Bekir Sami Yilbas
Keyword(s):  
Laser Welding ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Careful Examination ◽  
Welding Parameters ◽  
Weld Quality ◽  
Laser Weld ◽  
Power Intensity ◽  
Segregation Profile

Laser welding of steel 316L sheets is considered and the effects of laser welding parameters on the laser weld quality and metallurgical changes in the weld section are presented. The laser weld quality is assessed through careful examination of weld geometrical features, and the resulting weld microstructure. Metallurgical changes in the weld sites are examined using optical, and electron scanning microscope (SEM). Two levels of heat inputs are used-1500W and 2000W; and two scanning speeds of 2cm/s and 4cm/s are used to laser weld 316L sheets. It is found that at the high laser power intensities, evaporation takes place in the irradiated region and as the laser power intensity increases further, a cavity is formed at the top surface of the welding cross section. A similar situation is also observed as the laser scanning speed reduces. The low diffusivity of the alloying elements at high temperatures preserves the segregation profile. The scattered partitioning of the cells and dendrite boundaries are observed due to the presence of Cr and Mo.

Research on Microstructure and Wear Property of 45 Steel Quenched with Different Laser Power

2020 ◽  
Vol 861 ◽  
pp. 35-40
Author(s):  
Yu Liu ◽  
Tian Hao Xu ◽  
Ying Liu ◽  
Hai Cheng Zhang ◽  
Xing Xing Li ◽  
...  
Keyword(s):  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Wear Volume ◽  
Wear Property ◽  
Steel Matrix ◽  
Wear Properties ◽  
Laser Scanning Speed ◽  
Friction And Wear Properties ◽  
Minimum Wear

The surface of 45 steel is quenched by CO2 laser with scanning speed 1000 mm/min and different laser power 1000W, 1200W, 1400W, 1600W and 1800W. Experiments are carried out to analyze microstructure, friction and wear properties of quenched 45 steel. The results show that the quenching layer thickness increases gradually with the increase of laser power,and the maximum value of quenching layer hardness increases first and then decreases. When the laser power is 1600W, the maximum hardness value is 883HV0.5. But when the laser power is 1800W, the hardness of quenching layer becomes to decrease. The reason is the surface of 45 steel becomes to melt. The wear volume increases first and then decreases too. When laser power is 1600W, the minimum wear volume is 0.08mm3, which is 6.4% to the wear volume of 45 steel matrix without laser quenching. Therefore, better microstructure and properties of 45 steel can be obtained when laser scanning speed is 1000mm/min and laser power is 1600W.

scholarly journals Study of Infrared Laser Parameters on Surface Morphology and Hydrophobic Properties

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3860
Author(s):  
Xia Ye ◽  
Jiang Gu ◽  
Zhenmin Fan ◽  
Xiaohong Yang ◽  
Wei Xu
Keyword(s):  
Laser Power ◽  
Laser Scanning ◽  
Aging Treatment ◽  
Surface Characteristics ◽  
Scanning Speed ◽  
Infrared Laser ◽  
Energy Materials ◽  
Hydrophobic Properties ◽  
Low Surface Energy ◽  
Nano Structures

Many studies have shown that super hydrophobic surfaces have been applied to micro–nano structures and low surface energy materials. In the present study, infrared laser scanning and simple salinization modification were used to improve the hydrophobicity of a surface. When the scanning speed was 100 mm/s, the laser power was 30 W and the scanning interval was 200 μm, the apparent contact angle of surface was up to 157°. The assessment of surface characteristics revealed that decreasing scanning speed or increasing laser power were able to improve the hydrophobicity of the surface. After aging treatment, the superhydrophobic surface prepared by this method still had good durability.

scholarly journals The Study on Mechanical Strength of Titanium-Aluminum Dissimilar Butt Joints by Laser Welding-Brazing Process

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 712 ◽  
Author(s):  
Xiongfeng Zhou ◽  
Ji’an Duan ◽  
Fan Zhang ◽  
Shunshun Zhong
Keyword(s):  
Tensile Strength ◽  
Laser Welding ◽  
Welding Speed ◽  
Laser Power ◽  
Butt Joint ◽  
Interface Fracture ◽  
Welding Parameters ◽  
Fracture Roughness ◽  
Joint Properties ◽  
5A06 Aluminum Alloy

Laser welding–brazing of 5A06 aluminum to Ti6Al4V titanium in a butt configuration was carried out to discuss the influences of welding parameters on dissimilar joint properties. The effects of laser offset, welding speed, and laser power on the spreading length of the molten aluminum liquid, interface fracture zone width (IFZW), fracture roughness, intermetallic compounds (IMCs) thickness, and tensile strength were also investigated. The microstructure and fracture of the joint were also studied. The results show that the tensile strength of the joint is not only influenced by the thickness and type of IMCs, but also influenced by the spreading ability of the aluminum liquid, the fracture area broken at the Ti/fusing zone (FZ) interface, and the relative area of the brittle and ductile fracture in FZ. A dissimilar butt joint with an IMC thickness of 2.79 μm was obtained by adjusting the laser offset, welding speed, and laser power to 500 μm, 11 mm/s and 1130 W, respectively. The maximum tensile strength of the joint was up to 183 MPa, which is equivalent to 83% of the tensile strength of the 5A06 aluminum alloy.

scholarly journals A State-of-the-Art Review of Laser Welding of Polymers - Part I: Welding Parameters

2021 ◽  
Vol 100 (7) ◽  
pp. 221-228
Author(s):  
Nitesh Kumar ◽  
◽  
Nikhil Kumar ◽  
Asish Bandyopadhyay
Keyword(s):  
Laser Welding ◽  
Morphological Characteristics ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Welding Parameters ◽  
High Durability ◽  
Transmission Laser Welding ◽  
Automotive Parts ◽  
Important Field ◽  
Welding Processes

Polymers are widely used in automotive parts and fields like mechatronics and biomedical engineering because of their excellent properties, such as high durability and light weight. Welding of polymers has grown to be an important field of research due to its relevance among products of everyday life. Through transmission laser welding (TTLW) has been frequently selected by the contemporary re-searchers in the field of welding as it is relatively modern and more efficient than other welding processes. This pa-per reviews the influence of different processing parameters, including laser power, scanning speed, standoff distance, and clamping pressure. The present article is expected to provide the reader with a comprehensive under-standing of TTLW and research on the aforementioned four welding parameters in TTLW. The significance of finite element modeling, a few simulation studies, different optimization approaches, morphological characteristics, and other behaviors of laser welded polymers will be included in the next part of the review.

scholarly journals In Situ Mo(Si,Al)2-Based Composite through Selective Laser Melting of a MoSi2-30 wt.% AlSi10Mg Mixture

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3720 ◽  
Author(s):  
Tatevik Minasyan ◽  
Sofiya Aydinyan ◽  
Ehsan Toyserkani ◽  
Irina Hussainova
Keyword(s):  
High Temperature ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Laser Melting ◽  
Structural Applications ◽  
Laser Scanning Speed ◽  
Fusion Approach

The laser power bed fusion approach has been successfully employed to manufacture Mo(Si,Al)2-based composites through the selective laser melting of a MoSi2-30 wt.% AlSi10Mg mixture for high-temperature structural applications. Composites were manufactured by leveraging the in situ reaction of the components during printing at 150–300 W laser power, 500–1000 mm·s−1 laser scanning speed, and 100–134 J·mm−3 volumetric energy density. Microcomputed tomography scans indicated a negligible induced porosity throughout the specimens. The fully dense Mo(Si1-x,Alx)2-based composites, with hardness exceeding 545 HV1 and low roughness for both the top (horizontal) and side (vertical) surfaces, demonstrated that laser-based additive manufacturing can be exploited to create unique structures containing hexagonal Mo(Si0.67Al0.33)2.

Design and Realization of Auto-Programming System for SLS on CAD

2013 ◽  
Vol 662 ◽  
pp. 879-883
Author(s):  
Qing Guo Chen ◽  
Jun Cai Zhang
Keyword(s):  
Data Processing ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Numerical Control ◽  
Orthogonal Experimental Design ◽  
Programming System ◽  
Cross Sectional ◽  
Matching Rule ◽  
Scanning Velocity

The detail and design of numerical control system for SLS are discussed. With the help of Visuall C++ and tool kit ObjectARX in AutoCAD, the data information of the 2D contours are extracted from model in AutoCAD by data processing, and these data are transferred to laser scanning data, finally NC codes for processing are generated. A new kind of adaptive slicing algorithm that determines the slicing thickness by comprehensively considering the surface normal and the cross-sectional area, is adopted in data processing. The preheat temperature, scanning speed, laser power and thickness of spreading layer are main factors to part quality in Selective Laser Sintering(SLS). Sintering parameters are optimized by orthogonal experimental design. And a matching rule between scanning velocity and laser power is established so as to realize the laser power matching in different scanning velocities. In order to maintain and transplanted the system, the modular structure is used in the procedure of system design.

Influence of Process Parameters on the Mechanical Response of Various Layers Processed Using Direct Metal Laser Sintering (DMLS)

2014 ◽  
Author(s):  
S. Ahmed ◽  
H. Doak ◽  
A. Mian ◽  
R. Srinivasan
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Laser Power ◽  
Laser Scanning ◽  
Mechanical Response ◽  
Scanning Speed ◽  
Direct Metal Laser Sintering ◽  
Influence Of Process Parameters ◽  
Microstructural Morphology ◽  
Laser Scanning Speed

During the DMLS process, sintering of the top layer creates melting and heat affected zone in previously sintered layers. In this paper, we will examine the effects of any given process parameter, such as laser power and laser scanning speed, on the mechanical properties and microstructural morphology within the processed layers.

scholarly journals Mesoscopic simulation of overlapping behavior in laser powder bed additive manufacturing

2021 ◽  
Author(s):  
Pan Lu ◽  
Liu Tong ◽  
Wang Wen-hao ◽  
Gao Yu ◽  
Zhang Cheng-lin ◽  
...  
Keyword(s):  
Energy Density ◽  
Molten Pool ◽  
Laser Power ◽  
Laser Scanning ◽  
Flow Behavior ◽  
Pure Copper ◽  
Scanning Speed ◽  
Powder Bed ◽  
Volume Energy ◽  
Laser Scanning Speed

Abstract The prediction of the flow behavior of Metal micro-molten pool is prerequisite for high-quality Laser Powder Bed Fusion (L-PBF). In this study, mesoscopic scale numerical simulation modelling for L-PBF process was used to help understand the melting process of pure copper micro-melt pool.In this study, the orthogonal test was designed to study the influence of laser power, laser scanning velocity, hatching space on the flow behavior of molten pool and the overlapping rate of adjacent molten tracks. The results shows that laser scanning speed has the greatest influence on both the size and overlapping rate of the molten pool, and the overall trend was that the size of molten pool continues to increase as the volume energy density increases, and the maximum molten pool size was 243.6um × 110um with volume energy density 370.037 J/mm3, overlapping rate of adjacent molten tracks was 48.84% with volume energy density 285.71 J/mm3. The optimized pure copper laser process parameters were obtained: laser power 300 KW, laser scanning speed 500 mm/s, hatching space 0.07mm, overlapping rate 48.84%.

scholarly journals An Investigation on Laser Welding Parameters on the Strength of TRIP Steel

2021 ◽  
Vol 67 (1-2) ◽  
pp. 45-52
Author(s):  
S Khot Rahul ◽  
T Venkateshwara Rao ◽  
Natu Harshad ◽  
H N Girish ◽  
Tadashi Ishigaki ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Laser Welding ◽  
High Power ◽  
Heat Affected Zone ◽  
Trip Steel ◽  
Arc Welding ◽  
Laser Power ◽  
Welded Joint ◽  
Incident Angle ◽  
Welding Parameters

The energy required for joining steel segments by using laser welding is relatively very low compared with arc welding, gas welding, or any other conventional welding techniques. Moreover, the rapid cooling may create a significant effect on different regions, such as the fusion zone (FZ), heat affected zone (HAZ), and base metal (BM), and in turn affect different parameters. In this study, the characteristics of the laser-welded joint were investigated by varying laser power, welding velocity and incident angle, and tensile strength. In our, experiments. the microhardness was increased by varying the power of laser welding. The strength of the joint was increased to 549 MPa with 2200 W high power, 30 mm/s velocity, and 80º laser incident angle. By increasing the power and velocity of the laser, the welding gun strength was improved; conversely, the angle of laser incident on the welding location decreased while its strength was increased.

Numerical simulation and experimental study on laser hardening process of the 42CrMo4 steel

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110446
Author(s):  
Hongwei Zhang ◽  
Meng Zhu ◽  
Siqi Ji ◽  
Jianjun Zhang ◽  
Hengming Fan
Keyword(s):  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Element Model ◽  
Laser Hardening ◽  
Hardening Process ◽  
42Crmo4 Steel ◽  
Pitch Bearing ◽  
Laser Scanning Speed ◽  
The Finite Element Model

The large diameter pitch bearing was made of steel 42CrMo4 and the laser hardening process was used to improve its surface properties. In this paper, a numerical approach which can predict the temperature field and the hardened depth is provided for the laser hardening process of the 42CrMo4 steel. According to the simplification of the raceway structure of pitch bearing, the finite element model was constructed using ABAQUS software. Based on the actual process parameters, the transient thermal analysis was accomplished and the distribution of temperature field is analyzed. The hardened depth is determined according to the proposed temperature range. Laser power, laser scanning speed, and spot diameter were considered as input parameters, the experimental studies were performed based on orthogonal design in order to study the effects of process parameters. The finite element model is validated. The surface roughness and microstructure studies on treated surfaces were conducted. Also the micro-hardness testing was performed. The results show that the laser hardening increases surface hardness by about 3.8 times than that of the base material. The three parameters of laser power, laser scanning speed, and spot diameter have a coupling effect on the surface treatment. The input laser power density is more important.

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