Laser Cladding of Two Hardfacing Alloys Onto Cylindrical Low Alloy Steel Substrates With a High Power Direct Diode Laser

2007 ◽  
Author(s):  
Kevin C. Schoeffel ◽  
Yung C. Shin
Keyword(s):  
Laser Cladding ◽  
High Power ◽  
Feed Rate ◽  
Base Material ◽  
Powder Feed Rate ◽  
Track Width ◽  
Stellite 6 ◽  
Powder Feed ◽  
Clad Layer ◽  
Blown Powder

Blown-powder laser cladding is an efficient method for enhancing the surface properties of engineering components while preserving the properties of the base material. High power direct diode lasers (HPDDLs) offer wide beams with nearly uniform intensity distribution, allowing the deposition of wide clad tracks with flatter profiles than those produced with a Gaussian beam. In this work, a 4.0 kW HPDDL is used to perform blown-powder cladding on AISI 4140 and AISI 5150 steel shafts. The first part of the experiments concerns two-layer circumferential tracks created from two commonly used hardfacing alloys: Stellite 6 (Co-Cr alloy) and Nistelle 625 (Ni-Cr alloy). The effects of laser power and powder feed rate on the clad geometry are assessed. Increasing the powder feed rate and holding constant all other parameters decreases the track width-to-thickness aspect ratio. All tracks exhibit dendrite microstructures that are characteristic of powder-based clad tracks. The tracks exhibit no cracks or porosity. Energy dispersive X-ray (EDX) analysis reveals dilution of five percent or less between the clad and substrate materials. The second part of the experiments concerns overlapping of single-layer clad tracks in a continuous helical pattern on the substrate to form a layer that covers a large area. Clad layer thickness and inter-track porosity are measured to determine the optimum degree of overlap for producing a high-quality clad layer. The thickness of the resulting Stellite 6 and Nistelle 625 clad layers decreases as the overlap percentage decreases. No inter-track, interfacial, or bulk pores are present for any tests, comprising overlap percentages of 50% and lower.

Laser Cladding of Micro-Fluidic Channel Mold

2011 ◽  
Vol 216 ◽  
pp. 424-429
Author(s):  
Xu Yue Wang ◽  
H.R. Guo ◽  
Yong Bo Wu ◽  
Wen Ji Xu ◽  
D.M. Guo
Keyword(s):  
Laser Cladding ◽  
Feed Rate ◽  
Laser Power ◽  
Powder Feed Rate ◽  
Fluidic Channel ◽  
Powder Feed ◽  
Technical Requirements ◽  
Clad Layer ◽  
Cad Cam ◽  
Geometrical Dimensions

Laser cladding of micro-fluidic channels mold was performed using Nd:YAG laser and synchronous powder feeder. Influences of laser power and powder feed rate on clad layer geometrical dimensions and qualities were investigated. Results show that powder feed rate 1.5-2.5 g/min used obtains micro clad layers which meet geometrical dimensions’ requirement of micro-fluidic channels mold and combination of parameters laser power 400 W and powder feed rate 2.0 g/min achieves micro clad layer with better clad quality. Scanning paths of micro-fluidic channels mold was planned through CAD-CAM software. Using optimum parameters combination, multilayer laser cladding experiment was carried out and a sample of micro-fluidic channels mold was fabricated with expectative structure and hardness. A little milling and polishing makes the sample meet technical requirements, 0.2mm in height and 0.3mm in width. Fabricating a mold takes 15-20 min totally.

Laser Alloying with WC Ceramic Powder in Hot Work Tool Steel Using a High Power Diode Laser (HPDL)

2006 ◽  
Vol 15-17 ◽  
pp. 193-198 ◽  
Author(s):  
Marek Piec ◽  
Leszek Adam Dobrzański ◽  
Krzysztof Labisz ◽  
Ewa Jonda ◽  
Andrzej Klimpel
Keyword(s):  
Surface Layer ◽  
Tungsten Carbide ◽  
Diode Laser ◽  
Tool Steel ◽  
High Power ◽  
Feed Rate ◽  
Powder Feed Rate ◽  
Powder Feed ◽  
Power Diode ◽  
High Power Diode Laser

Investigations include alloying the X38CrMoV5-3 hot-work tool steel surface layer with the tungsten carbide, using the high power diode laser (HPDL). The tungsten carbide ceramic particles of the medium grain size according to FSSS = 50 /m were introduced using the rotor conveyer to improve the properties of the surface layer. The powder feed rate was set at the steady level of 8.64g/min. Remelting and alloying were carried out several times in the laser power range of 1.2 – 2.3 kW in the remelting/alloying, alloying/remelting sequences. The structural mechanism was determined of gradient layer development, effect was studied of alloying parameters, gas protection method, and powder feed rate on its mechanical properties, and especially on its hardness, abrasive wear resistance, and roughness. Structure changes were revealed consisting, in particular, in its refining, and also hardness and microhardness changes in comparizon to the nonremelted steel. Examination results obtained with the EDX microanalysis, surface and linear analysis of the chemical composition, as well as the X-ray qualitative phase analysis are presented.

Processing parameter, microstructure and hardness of Ni base intermetallic alloy coating fabricated by laser cladding

MRS Advances ◽  
2017 ◽  
Vol 2 (26) ◽  
pp. 1381-1386 ◽  
Author(s):  
Takeshi Okuno ◽  
Yasuyuki Kaneno ◽  
Takuto Yamaguchi ◽  
Takayuki Takasugi ◽  
Satoshi Semboshi ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Feed Rate ◽  
Laser Power ◽  
Alloy Coating ◽  
Intermetallic Alloy ◽  
Ingot Metallurgy ◽  
Processing Parameter ◽  
Powder Feed Rate ◽  
Cladding Layer ◽  
Powder Feed

ABSTRACTNi base intermetallic alloy coating was fabricated by laser cladding, controlling the laser power and powder feed rate. Atomized powder of the Ni base intermetallic alloy was laser-cladded on the substrate of stainless steel 304. The hardness and microstructure of the clad layers were investigated by Vickers hardness test, SEM, XRD and TEM observations. The hardness of the cladding layer was affected by the dilution with the substrate; it increased with decreasing laser power and increasing powder feed rate. By optimizing the dilution with the substrate, the cladding layer with an almost identical hardness level to that of the Ni base intermetallic alloy fabricated by ingot metallurgy was obtained. The TEM observations revealed that a very fine-sized microstructure composed of Ni3Al and Ni3V was partially formed even in the as-cladded state. After annealing, the two-phase microstructure composed of Ni3Al and Ni3V was developed in the cladding layer, resulting in enhanced hardness in the cladding layers fabricated in the majority of cladding conditions.

Structure and Properties of Gradient Layers Using High Power Diode Laser

2006 ◽  
Vol 530-531 ◽  
pp. 269-274
Author(s):  
Leszek Adam Dobrzański ◽  
Marek Piec ◽  
Zuzanka Trojanová ◽  
Józef Lelątko ◽  
Andrzej Klimpel
Keyword(s):  
Surface Layer ◽  
Tungsten Carbide ◽  
Diode Laser ◽  
High Power ◽  
Feed Rate ◽  
Powder Feed Rate ◽  
Powder Feed ◽  
Protection Method ◽  
Power Diode ◽  
High Power Diode Laser

Investigations include alloying the X38CrMoV5-3 hot-work tool steel surface layer with the tungsten carbide, using the high power diode laser (HPDL). The tungsten carbide ceramic particles of the medium grain size according to FSSS = 50 Bm were introduced using the rotor conveyer to improve the properties of the surface layer. The powder feed rate was set at the steady level of 8.64g/min. Remelting and alloying were carried out several times in the laser power range of 1.2 – 2.3 kW in the remelting/alloying, alloying/remelting sequences. The structural mechanism was determined of gradient layer development, effect was studied of alloying parameters, gas protection method, and powder feed rate on its mechanical properties, and especially on its hardness, abrasive wear resistance, and roughness. Structure changes were revealed consisting, in particular, in its refining, and also hardness and microhardness changes in comparison to the non-remelted steel. Examination results obtained with the EDX microanalysis, surface and linear analyses of the chemical composition, as well as the X-ray qualitative phase analysis are presented.

scholarly journals Crack Sensitivity Control of Nickel-Based Laser Coating Based on Genetic Algorithm and Neural Network

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 728 ◽  
Author(s):  
Yu ◽  
Sun ◽  
Huang ◽  
Wang ◽  
Wang ◽  
...  
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Laser Cladding ◽  
Process Parameters ◽  
Feed Rate ◽  
Crack Density ◽  
Scanning Speed ◽  
Powder Feed Rate ◽  
Powder Feed ◽  
Overlap Rate

This paper aimed to establish a nonlinear relationship between laser cladding process parameters and the crack density of a high-hardness, nickel-based laser cladding layer, and to control the cracking of the cladding layer via an intelligent algorithm. By using three main process parameters (overlap rate, powder feed rate, and scanning speed), an orthogonal experiment was designed, and the experimental results were used as training and testing datasets for a neural network. A neural network prediction model between the laser cladding process parameters and coating crack density was established, and a genetic algorithm was used to optimize the prediction results. To improve their prediction accuracy, genetic algorithms were used to optimize the weights and thresholds of the neural networks. In addition, the performance of the neural network was tested. The results show that the order of influence on the coating crack sensitivity was as follows: overlap rate > powder feed rate > scanning speed. The relative error between the predicted value and the experimental value of the three-group test genetic algorithm-optimized neural network model was less than 9.8%. The genetic algorithm optimized the predicted results, and the technological parameters that resulted in the smallest crack density were as follows: powder feed rate of 15.0726 g/min, overlap rate of 49.797%, scanning speed of 5.9275 mm/s, crack density of 0.001272 mm/mm2. Therefore, the amount of crack generation was controlled by the optimization of the neural network and genetic algorithm process.

scholarly journals Study on the Deformation Control and Microstructures of Thin-Walled Parts Repaired by Laser Cladding

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 369 ◽  
Author(s):  
Jiangtong Yu ◽  
Wenlei Sun ◽  
Haibo Huang ◽  
Yong Huang
Keyword(s):  
Laser Cladding ◽  
Feed Rate ◽  
Laser Power ◽  
Visual Analysis ◽  
Scanning Speed ◽  
Powder Feed Rate ◽  
Dendritic Crystal ◽  
Powder Feed ◽  
Minimum Deformation ◽  
Thin Walled

To reduce the deformation and improve the quality of thin-walled parts repaired by laser cladding, a three-factor, three-level orthogonal experimental scheme was employed to clad Ni60 powder on thin-walled parts with a thickness of 3.5 mm. To measure the deformation of the thin-walled parts, a method of combining the meshing of the backs of the thin-walled parts and fixing one end of the parts during cladding was used. The effects of the powder feed rate, laser power, and scanning speed on the deformation of the thin-walled parts were studied via visual analysis and analysis of variance, and the process parameters that resulted in the minimum deformation were determined. The deformation process of the thin-walled parts and the causes of cladding stress were also studied, and the microstructure of the cladding layer with the minimum deformation was analyzed via scanning electron microscopy (SEM). The results reveal that the deformation of the thin-walled parts increased with the increase of laser power. The increases of the scanning speed and powder feed rate were found to reduce the deformation of thin-walled parts; the laser power was found to have a significant effect, and the powder feed rate was found to have no significant effect, on the deformation of thin-walled parts. The order of the influence of factors on the deformation of thin-walled parts from greatest to least was determined to be as follows: laser power > scanning speed > powder feed rate. The optimal parameters to obtain the minimum deformation and good metallurgical bonding of thin-walled parts were found to be a powder feed rate of 1.4 r/min, a laser power of 1100 W, and a scanning speed of 8 mm/s. From the bottom to the top, the crystal structure of the coating with the minimum deformation was found to be coarse dendrite, dendritic crystal, and equiaxed crystal.

Study on Macroscopic Morphology, Microstructure and Hardness of F313 Iron-Based Coatings Prepared by Laser Cladding Using Different Powder Feed Rate

2015 ◽  
Vol 1095 ◽  
pp. 631-635 ◽  
Author(s):  
You Zheng Sun ◽  
Shuai Liu ◽  
Si Yu Wang ◽  
Jin Bao Li ◽  
Chuan Ning Yang ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Cross Sections ◽  
Vickers Hardness ◽  
Feed Rate ◽  
Eutectic Structure ◽  
Powder Feed Rate ◽  
Lower Region ◽  
Hardness Tester ◽  
Powder Feed ◽  
Iron Based

The objective of the present study was to find the influence of powder feed rate on macroscopic morphology, microstructure and hardness of F313 iron-based alloy clad coatings. Controlling powder feed rate can assist with achieving favorable macroscopic morphology, microstructure and hardness. Four different powder feed rate were used in our experiments to prepare clad coatings. The macroscopic morphology, microstructure and hardness were tested using OM, SEM, and Vickers hardness tester. The study founds decreasing powder feed rate is possible to achieve smoother surface, but at the same time thickness of coatings get thinner. Microstructure of cross sections is divided into inter-dendrites eutectic structure and dendritic matrix. In the upper region the microstructure tends to be formed of cellular-like dendrites whereas in the lower region branch-like dendrites tend to form. Hardness decreases with increasing of powder feed rate generally.

Multi-Objective Optimisation of Laser Deposition of Metal Matrix Composites for Surface Coating Using Principal Component Analysis

2018 ◽  
Vol 40 ◽  
pp. 9-21 ◽  
Author(s):  
Peter Kayode Farayibi
Keyword(s):  
Feed Rate ◽  
Surface Coating ◽  
Laser Power ◽  
Traverse Speed ◽  
Laser Deposition ◽  
Powder Feed Rate ◽  
Multi Objective ◽  
Powder Feed ◽  
Output Characteristics ◽  
Wire Feed

Laser deposition is an advanced manufacturing technology capable of enhancing service life of engineering components by hard-facing their functional surfaces. There are quite a number of parameters involved in the process and also desirable output characteristics. These output characteristics are often independently optimised and which may lead to poor outcome for other characteristics, hence the need for multi-objective optimisation of all the output characteristics. In this study, a laser deposition of Ti-6Al-4V wire and tungsten carbide powder was made on a Ti-6Al-4V substrate with a view to achieve a metallurgical bonded metal matrix composite on the substrate. Single clads were deposited with a desire to optimise the composite clad characteristics (height, width and reinforcement fraction) for the purpose of surface coating. Processing parameters (laser power, traverse speed, wire feed rate, powder feed rate) were varied, the experiment was planned using Taguchi method and output characteristics were analysed using principal component analysis approach. The results indicated that the parameters required for optimised clad height, width, and reinforcement fraction necessary for surface coating is laser power of 1800 W, traverse speed of 200 mm/min, wire feed rate 700 mm/min and powder feed rate of 30 g/min. The powder feed rate was found to most significantly contribute 43.99%, followed by traverse speed 39.77%, laser power 15.87% with wire feed rate having the least contribution towards the multi-objective optimisation. Confirmation results showed that clad width and reinforcement fraction were significantly improved by the optimised parameters. The multi-objective optimisation procedure is a useful tool necessary to identify the process factors required to enhance output characteristics in laser processing.

Novel Liquid Fuel HVOF Torches Fueled with Ethanol: Optimization and Erosion Wear Response of Cr3C2-NiCr Coatings

2021 ◽  
Author(s):  
Shaowu Liu ◽  
Michel Moliere ◽  
Hanlin Liao
Keyword(s):  
Flow Rate ◽  
Feed Rate ◽  
Impact Angle ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
Standoff Distance ◽  
Wear Loss ◽  
Erosion Wear ◽  
Powder Feed Rate ◽  
Powder Feed

Abstract In this work; a novel liquid fuel HVOF process fueled with ethanol was used to prepare 75wt%Cr3C2–25wt%NiCr coatings on AISI304 stainless steel substrate. Taguchi method was employed to optimize the spray parameters (ethanol flow rate; oxygen flow rate; powder feed rate and standoff distance) to achieve better erosion resistance at 90° impact angle. The results indicated that ethanol flow rate and oxygen flow rate were identified as the highly contributing parameters on the erosion wear loss. The important sequence of the spray parameter is ethanol flow rate > oxygen flow rate > standoff distance > powder feed rate. The optimal spray parameter (OSP) for minimum erosion wear loss was obtained under ethanol flow rate of 28slph; oxygen flow rate of 420slpm; powder feed rate of 76.7 g/min and standoff distance of 300mm. The phase composition; microstructure; hardness; porosities; and the erosion wear behaviors of the coatings have been studied in detail. Besides; erosion wear testing of the optimized coating was conducted at 30°; 60° and 90° impact angle using air jet erosion testing machine. The SEM images of the erodent samples were taken to analyze the erosion mechanism.

Study on optimization of laser cladding using Stellite 6 powder for exhaust valve face of marine engine

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940037 ◽  
Author(s):  
Moo-Keun Song ◽  
Su-Han Park ◽  
Su-Jin Lee ◽  
Jong-Do Kim
Keyword(s):  
Heat Source ◽  
Laser Cladding ◽  
Exhaust Valve ◽  
Optimum Conditions ◽  
Marine Engine ◽  
Stellite 6 ◽  
Average Hardness ◽  
Clad Layer ◽  
Power Diode ◽  
High Power Diode Laser

In this study, experiments with various parameters were performed to apply laser cladding to the exhaust valve face of a marine engine and optimum conditions were derived. The used specimen was an actual exhaust valve, and the heat source was a high-power diode laser. Cladding was applied to the exhaust valve face using the optimum conditions, and a sound clad layer without internal defects, such as pores and cracks, was formed. The average hardness of the clad layer formed under the optimum conditions was higher than 529 Hv. Component analysis showed a very low dilution rate inside the clad layer.

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