Experimental Study Based on the Widening Melting Roads Cladding Forming of the Hollow Laser

2013 ◽  
Vol 419 ◽  
pp. 180-185
Author(s):  
Liang Liang Yu ◽  
Shi Hong Shi ◽  
Ge Yan Fu ◽  
Mei Ling Tian
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Research Group ◽  
Laser Power ◽  
New Technology ◽  
Scanning Speed ◽  
Feeding Speed ◽  
Series Of Experiments ◽  
Cladding Layers ◽  
Powder Feeding

Our research group has invented a kind of new technology called coaxial inside-beam powder feeding. By series of experiments, this paper analyzed and summarized the process parameters’ influence on the cladding layers’ feature and quanlity, which contain the laser power P, the powder feeding speed Vf, the scanning speed Vs and the defocusing distance L. Some cladding experiments also were made to aquire the cladding roads with variable width. The experimental results indicate that when P, Vf and D×Vs are fixed, roads with stable height and uniformly changing width are acquired by changing Vs and L at the same time.

Study on the Laser Alloy Cladding for Re-Manufacturing of the Surface of 40Cr

2015 ◽  
Vol 713-715 ◽  
pp. 2900-2904
Author(s):  
Yan Li Zhang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Process Parameters ◽  
Laser Power ◽  
Scanning Speed ◽  
Laser Alloy ◽  
Hardness Tester ◽  
Cladding Layer ◽  
Cladding Layers ◽  
Scanning Electron

The laser alloy cladding technology is used to treat the surface of 40Cr, and the two alloy powders are used separately. The process parameters are different, such as laser power, feed rate and scanning speed etc. The microstructure and hardness of cladding layers are analyzed by using scanning electron microscope and hardness tester. Generally, the surface quality is improved apparently. Under the similar laser power and powder quantity, the thickness of Ni60 cladding layer is much larger than Fe60. The hardness of Ni60 layer and Fe60 layer are all higher than substrate. There are more cracks in Ni60 layer than in Fe60 layer. The parameters of sample No.1 is optimal.

Parameter optimisation of laser cladding repair for an Invar alloy mould

2018 ◽  
Vol 233 (8) ◽  
pp. 1859-1871 ◽  
Author(s):  
Shichao Zhu ◽  
Wenliang Chen ◽  
Xiaohong Zhan ◽  
Liping Ding ◽  
Junjie Zhou
Keyword(s):  
Dilution Rate ◽  
Laser Cladding ◽  
Laser Power ◽  
Scanning Speed ◽  
Advanced Technology ◽  
Invar Alloy ◽  
Geometric Features ◽  
Feeding Rates ◽  
Cladding Layer ◽  
Powder Feeding

Laser cladding repair is an advanced technology for repairing Invar alloy moulds; however, the influences of various processing parameters on the quality of the Invar alloy moulds have yet to be determined. To explore the optimisation of laser cladding repair parameters, analyses of the geometric features and microstructure of the cladding layer were conducted. First, the influences of different powder feeding rates and scanning speeds on the dilution rate of the substrate were investigated by establishing a mathematical model of the laser power attenuation. Next, the influences of the parameters on the geometric features of the cladding layer were analysed. Finally, the influences of the parameters on the microstructure of the cladding layer were evaluated. At a laser power of 2300 W, a scanning speed of 3 m/min, and a powder feeding rate of 9 g/min, the best results of the width, height, dilution rate, roughness, and contact angle of the cladding layer were obtained. The results of this study indicated that excellent metallurgical bonding occurred between the cladding layer and the interface layer, and that the intended geometric features and desired microstructure of the cladding layer were obtained.

Research on Warpage of Polystyrene in Selective Laser Sintering

2010 ◽  
Vol 43 ◽  
pp. 578-582 ◽  
Author(s):  
C.Y. Wang ◽  
Q. Dong ◽  
X.X. Shen
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Laser Power ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Main Process ◽  
Influence Of Process Parameters ◽  
Temperature Changes ◽  
Hatch Spacing

Warpage is a crucial factor to accuracy of sintering part in selective laser sintering (SLS) process. In this paper, The influence of process parameters on warpage when sintering polystyrene(PS) materials in SLS are investigated. The laser power, scanning speed, hatch spacing, layer thickness as well as temperature of powder are considered as the main process parameters. The results showed that warpage increases with the increase of hatch space. Contary to it, warpage decreases with the increase of laser power. Warpage decreases with the increase of layer thickness between 0.16~0.18mm and changes little with increase of the thickness. Warpage increases along with the increase of scanning speed but decreases when the speed is over about 2000mm/s. When the temperature changes between 82°C-86°C, warpage decreases little with the increase of temperature. But further increase of temperature leads to warpage decreasing sharply when the temperature changes between 86°C-90°C.

Experimental Study of Forming Rene95 Alloy Parts by Laser Cladding

2001 ◽  
Author(s):  
Qilin Deng ◽  
Dejin Hu ◽  
Jingyu Pei ◽  
Wenwu Zhang ◽  
Y. Lawrence Yao
Keyword(s):  
Experimental Study ◽  
Laser Cladding ◽  
Laser Power ◽  
Alloy Powder ◽  
High Strength ◽  
Scanning Speed ◽  
Main Process ◽  
Beam Diameter ◽  
Laser Beam Diameter ◽  
Metal Parts

Abstract In this paper, experimental study of forming metal parts by laser cladding Rene95 alloy powder was reported. The influence of main process parameters, such as laser power, scanning speed and laser beam diameter, on the thickness, width and the angle of the laser cladding track was investigated. The microstructures of laser cladding parts were studied and compared with those of common casting parts. The obtained Rene95 metal parts formed by laser cladding are dense and of high strength.

scholarly journals Numerical Simulation of Moving Heat Flux during Selective Laser Melting of AlSi25 Alloy Powder

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 877
Author(s):  
Cong Ma ◽  
Xianshun Wei ◽  
Biao Yan ◽  
Pengfei Yan
Keyword(s):  
Numerical Simulation ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Molten Pool ◽  
Laser Power ◽  
Scanning Speed ◽  
Powder Layer ◽  
Maximum Temperature ◽  
Three Dimensional Model ◽  
Laser Melting

A single-layer three-dimensional model was created to simulate multi-channel scanning of AlSi25 powder in selective laser melting (SLM) by the finite element method. Thermal behaviors of laser power and scanning speed in the procedure of SLM AlSi25 powder were studied. With the increase of laser power, the maximum temperature, size and cooling rate of the molten pool increase, while the scanning speed decreases. For an expected SLM process, a perfect molten pool can be generated using process parameters of laser power of 180 W and a scanning speed of 200 mm/s. The pool is greater than the width of the scanning interval, the depth of the molten pool is close to scan powder layer thickness, the temperature of the molten pool is higher than the melting point temperature of the powder and the parameters of the width and depth are the highest. To confirm the accuracy of the simulation results of forecasting excellent process parameters, the SLM experiment of forming AlSi25 powder was carried out. The surface morphology of the printed sample is intact without holes and defects, and a satisfactory metallurgical bond between adjacent scanning channels and adjacent scanning layers was achieved. Therefore, the development of numerical simulation in this paper provides an effective method to obtain the best process parameters, which can be used as a choice to further improve SLM process parameters. In the future, metallographic technology can also be implemented to obtain the width-to-depth ratio of the SLM sample molten pool, enhancing the connection between experiment and theory.

Influence of the Parameters on the Laser Deposited TiAl Layer

2011 ◽  
Vol 306-307 ◽  
pp. 496-499 ◽  
Author(s):  
Yuan Bin Zhang ◽  
Bai Ying Huang ◽  
Huai Xue Li
Keyword(s):  
Intermetallic Compound ◽  
Laser Power ◽  
Scanning Speed ◽  
Interface Layer ◽  
Alloy Surface ◽  
Metal Powders ◽  
Ta15 Alloy ◽  
Tial Layer ◽  
Cladding Layers

TiAl based intermetallic compound claddings were produced on TA15 alloy surface by using laser depositing technology to melt Ti-46Al-2Cr metal powders. An interface layer between TA15 substrate and the TiAl claddings was formed. The influence of laser power, scanning speed and number of cladding layers on the interface layer and the hardness of TiAl claddings were investigated. Higher laser power and lower scanning speed made the interface layer thicker. Increasing the laser power and especially the scanning speed could improve the hardness of the TiAl claddings. When the second TiAl layer was deposited, there was no interface layer formed between the two TiAl layers, but the hardness of the first layer decreased and the second TiAl layer was softer than the first layer due to the rough microstructure.

Study on the Process Parameters of MPAW-Based Rapid Prototyping

2007 ◽  
Vol 353-358 ◽  
pp. 1931-1934
Author(s):  
Wurikaixi Aiyiti ◽  
Wan Hua Zhao ◽  
Yi Ping Tang ◽  
Bing Heng Lu
Keyword(s):  
Rapid Prototyping ◽  
Process Parameters ◽  
Gas Flow ◽  
Scanning Speed ◽  
Part Quality ◽  
R Ratio ◽  
Feeding Speed ◽  
Wire Feeding ◽  
The Impact

A direct metal RP (rapid prototyping) process based on micro-plasma arc welding (MPAW) is presented. The impact of R (ratio of width to height of the deposited track’s cross-section) on part quality is investigated. Taguchi method is adopted to analyze the effect of each process parameter on R, and the optimized process parameters are obtained. The results show that the quality of the parts with larger R is better than that with smaller R, and the peak current, duty cycle of pulse duration, wire-feeding speed, scanning speed and plasma gas flow rate all exert significant effects on R. The overlapped surface smoothness, tensile strength and elongation of the parts fabricated with optimized parameters are measured to show obviously better performances than those of the parts fabricated with ordinary process parameters.

scholarly journals Preliminary Testing to Determine the Best Process Parameters for Polymer Laser Sintering of a New Polypropylene Polymeric Material

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Fredrick M. Mwania ◽  
Maina Maringa ◽  
Jakobus. G. van der Walt
Keyword(s):  
Mechanical Properties ◽  
Polymeric Material ◽  
Process Parameters ◽  
Laser Power ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Process Conditions ◽  
Preliminary Testing ◽  
Chamber Temperature ◽  
Suitable Process

Polymer laser sintering is an elaborate additive manufacturing technique because it is subject to process parameters and material properties. In this regard, each polymeric material necessitates a different set of process conditions. To this end, testing was done to determine the most suitable process parameters for a new commercially available polymer (Laser PP CP 60), from Diamond Plastics GmbH. It was established that the material requires slightly different settings from those provided by the supplier for the values for the removal chamber temperature, building chamber temperatures, and laser power to achieve the best mechanical properties (ultimate tensile strength). The preliminary testing indicates that the process parameters that yielded the best mechanical properties for the laser PP CP 60 powder were 125°C, 125°C, 0.15 mm, 250 μm, 4500 mm/s, 34.7 W, 1500 mm/s, and 21.3 W for the removal chamber temperature, building chamber temperature layer thickness, hatch distance, scanning speed fill, laser power fill, scanning speed contour, and laser power contour, respectively.

scholarly journals Multi-objective numerical simulation of geometrical characteristics of laser cladding of cobalt-based alloy based on response surface methodology

2020 ◽  
pp. 002029402094495
Author(s):  
Lu-jun Cui ◽  
Meng Zhang ◽  
Shi-Rui Guo ◽  
Yan-Long Cao ◽  
Wen-Han Zeng ◽  
...  
Keyword(s):  
Prediction Model ◽  
Response Surface ◽  
Laser Cladding ◽  
Process Parameters ◽  
Laser Power ◽  
Influence Factors ◽  
Scanning Speed ◽  
Laser Cladding Remanufacturing ◽  
Main Influence

The objectives of this study are to optimize the key process parameters of laser cladding remanufacturing parts, improve the sealing quality of the hemispherical valve and prolong and improve its service life and reliability. A high-power fiber-coupled semiconductor laser was used to fabricate a single Co-based alloy cladding layer on the pump valve material ZG45 plate. The key process parameters of laser power, scanning speed and powder feeding rate in the process of laser remanufacturing are taken as optimization variables, and the coating width, coating height, coating depth, aspect ratio and dilution rate are taken as response indexes. Based on the response surface analysis method, the central compound experiment is designed using Design-Expert software. The variance analysis of the experimental results is performed, and the regression prediction model of the process parameters relative to the corresponding index is established. Through analysis of the established perturbation diagram and three-dimensional response surface, it is concluded that the main influence factors of melting width and penetration depth are laser power and positive effect, and the main influence factors of melting height are scanning speed and negative effect. The average error of each regression prediction model is lower than 10%. The above research work has important guiding significance for optimizing the process parameters and improving the cladding quality of cobalt-based alloy on ZG45.

Research on Technics of Laser Direct Metal Deposition Forming Technology

2009 ◽  
Vol 69-70 ◽  
pp. 54-58
Author(s):  
Wei Zhang ◽  
Jian Hua Yao
Keyword(s):  
Laser Power ◽  
Scanning Speed ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Solidification Velocity ◽  
Technological Parameters ◽  
Technical Parameters ◽  
Forming Technology ◽  
Average Hardness ◽  
Feeding Speed

The technological parameters of laser direct metal deposition (DMD) were researched by DMD forming experiments using 2Cr13 powder. Fixing other parameters, the lower of laser power, the smaller the characteristic sizes of cladding layer are. Increasing of laser power, cladding height would firstly increase and then decrease, cladding width would firstly increase and then almost maintain constant, while cladding depth would gradually increase. When other parameters are invariable, with increasing of powder feeding speed, cladding height would increase, cladding width and cladding depth would decrease. When other parameters are invariable, cladding width, cladding height and cladding depth would decrease with the adding of scanning speed. The microstructure of single track cladding had three typical patterns, cellular dendritic, column dendritic and equiaxed crystal. The patterns depended on the temperature gradient and the solidification velocity. Under different technical parameters, the average hardness of specimens would change from 300HV0.2 to 550HV0.2.

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