Effect of laser power and powder feed rate on interfacial crack and mechanical/microstructural characterizations in repairing of 630 stainless steel using direct energy deposition

2021 ◽  
pp. 142004
Author(s):  
Tae Geon Kim ◽  
Do Sik Shim
Keyword(s):  
Stainless Steel ◽  
Feed Rate ◽  
Laser Power ◽  
Energy Deposition ◽  
Interfacial Crack ◽  
Powder Feed Rate ◽  
Direct Energy Deposition ◽  
Powder Feed ◽  
Direct Energy

scholarly journals Optimizing the Characteristics of the Laser Hardfacing Process Parameters to Maximize the Wear Resistance of Ni-Based Hard-Faced Deposits Using the RSM Technique

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
S. Gnanasekaran ◽  
Samson Jerold Samuel Chelladurai ◽  
T. Ramakrishnan ◽  
S Sivananthan ◽  
G. Padmanaban ◽  
...  
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Process Parameters ◽  
Feed Rate ◽  
Laser Power ◽  
Travel Speed ◽  
Powder Feed Rate ◽  
Powder Feed ◽  
Rsm Technique

The nickel-based Colmonoy-5 hardfacing alloy is used to hard-face 316LN austenitic stainless steel components in fast reactors. The nominal composition (in wt%) was listed as follows: 0.01 C, 0.49 Si, 0.87 Mn, 17.09 Cr, 14.04 Ni, 2.56 Mo, 0.14 N, and balance Fe. Hardfacing is a technique of applying hard and wear-resistant materials to substrates that need abrasion resistance. The thickness of hardfacing deposit varies between 0.8 mm and 2 mm based on parameter combinations. In this study, laser hardfacing process parameters including laser power, powder feed rate, travel speed, and defocusing distance were optimized to reduce weight loss of laser hard-faced Ni-based deposit. The tribological characteristics of reactor-grade NiCr-B hard-faced deposits were investigated. The RSM technique was used to identify the most important control variables resulting in the least weight loss of the nickel-based alloy placed on AISI 316LN austenitic stainless steel. Statistical techniques like DoE and ANOVA are utilized. Changing the laser settings may efficiently track the weight loss of laser hard-faced nickel alloy surfaces. These are created using the response surface technique. The deposit produced with a laser power of 1314 W, powder feed rate of 9 g/min, travel speed of 366 mm/min, and defocusing distance of 32 mm had the lowest weight loss of 16.4 mg. Based on the F value, the powder feed rate is the major influencing factor to predict the hardness followed by power, travel speed, and defocusing distance.

Effect of Process Parameters on Laser Directed Energy Deposition of Copper

2019 ◽  
Author(s):  
Sunil Yadav ◽  
Christ P. Paul ◽  
Arackal N. Jinoop ◽  
Saurav K. Nayak ◽  
Arun K. Rai ◽  
...  
Keyword(s):  
Process Parameters ◽  
Feed Rate ◽  
Laser Power ◽  
Energy Deposition ◽  
Process Conditions ◽  
Powder Feed Rate ◽  
Track Geometry ◽  
Powder Feed ◽  
Directed Energy Deposition ◽  
Directed Energy

Abstract Laser Additive Manufacturing (LAM) is an advanced manufacturing processes for fabricating engineering components directly from CAD Model by depositing material in a layer by layer fashion using lasers. LAM is being widely deployed in various sectors such as power, aerospace, automotive etc. for fabricating complex shaped and customized components. One of the most commonly used LAM process is Directed Energy Deposition (LAM-DED) which is used for manufacturing near net shaped components with tailored microstructure, multi-materials (direct and graded) and complex geometry. This paper reports experimental investigation of LAM of Copper (Cu) tracks on Stainless Steel 304 L (SS 304L) using an indigenously developed LAM-DED system. Cu-SS304L joints find wider applications in tooling, automotive and aerospace sectors due to its combination of higher strength, thermal conductivity and corrosion resistance. However, laying Cu layers on SS304L is not trivial due to large difference in the thermo-physical properties. Thus, a comprehensive experiments using full factorial design are carried out and a number of Cu tracks were laid on SS304L substrate by varying laser power, scan speed and powder feed rate. The laid tracks are characterized for track geometry and porosity and the quality of the tracks are analyzed. Lower values of laser power and higher powder feed rate results in discontinuous deposition, while higher laser power and lower powder feed rate results in cracked deposits. Porosity is observed to vary from 6–45 % at different process conditions. Analysis of Variance (ANOVA) of deposition rate and track geometry is performed to estimate the major contributing process parameters. This study paves a way to understand effect of process parameters on LAM-DED for fabricating bimetallic joints and graded structures of Copper and SS304L.

Parametric investigation and characterization on SS316 built by laser-assisted directed energy deposition

2019 ◽  
Vol 234 (3) ◽  
pp. 452-466 ◽  
Author(s):  
K Benarji ◽  
Y Ravi Kumar ◽  
CP Paul ◽  
AN Jinoop ◽  
KS Bindra
Keyword(s):  
Deposition Rate ◽  
Process Parameters ◽  
Feed Rate ◽  
Laser Power ◽  
Energy Deposition ◽  
Scanning Speed ◽  
Powder Feed Rate ◽  
Parametric Investigation ◽  
Powder Feed ◽  
Directed Energy

In the present work, parametric investigation and characterization of stainless steel 316 (SS316) built by laser-assisted directed energy deposition (L-DED) is performed. Single-track L-DED experiments are carried by varying laser power, scanning speed, and powder feed rate using full factorial experimental design. The effect of L-DED process parameters on the track geometry, deposition rate, and microhardness is investigated, and three different combinations of process parameters yielding maximum deposition rate and hardness are identified for bulk investigation. The identified process parameters are laser power of 1000 W, powder feed rate of 8 g/min, and scanning speed of 0.4 m/min, 0.5 m/min, and 0.6 m/min. The austenitic phase [Formula: see text] is detected at all the conditions. However, ferrite [Formula: see text] peak is observed at 0.6 m/min due to microsegregation and thermal gradients. The minimum crystallite size is estimated to be 24.88 nm at 0.6 m/min. The porosity and microstructure analysis is carried out by optical microscopic images. The fine columnar dendritic structure is observed in L-DED samples at all conditions. An average microhardness of 317.4 HV0.98 N is obtained at 0.4 m/min, and it is observed that microhardness reduces with an increase in scanning speed mainly due to increase in lack of fusion and porosity. Tribology studies are carried out at different values of normal load and sliding velocity. The minimum specific wear rate of 0.02497 × 10−4 mm3/Nm is observed at scanning speed of 0.4 m/min. Scanning electron microscope of the wear tracks analysis shows abrasive wear as the major wear mechanism. This study provides a path for building SS316 components for various engineering applications.

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.

Direct energy deposition metamodeling using a meshless method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Boussad Abbes ◽  
Tahar Anedaf ◽  
Fazilay Abbes ◽  
Yuming Li
Keyword(s):  
Surrogate Model ◽  
Manufacturing Process ◽  
Laser Power ◽  
Energy Deposition ◽  
Feeding Rate ◽  
Maximum Temperature ◽  
Direct Energy Deposition ◽  
Content Type ◽  
Direct Energy ◽  
Powder Feeding

Purpose Direct energy deposition (DED) is an additive manufacturing process that allows to produce metal parts with complex shapes. DED process depends on several parameters, including laser power, deposition rate and powder feeding rate. It is important to control the manufacturing process to study the influence of the operating parameters on the final characteristics of these parts and to optimize them. Computational modeling helps engineers to address these challenges. This paper aims to establish a framework for the development, verification and application of meshless methods and surrogate models to the DED process. Design/methodology/approach Finite pointset method (FPM) is used to solve conservation equations involved in the DED process. A surrogate model is then established for the DED process using design of experiments with powder feeding rate, laser power and scanning speed as input parameters. The surrogate model is constructed using neutral networks (NN) approximations for the prediction of maximum temperature, clad angle and dilution. Findings The simulations of thin wall built of Ti-6Al-4V titanium alloy clearly demonstrated that FPM simulation is successful in predicting temperature distribution for different process conditions and compare favorably with experimental results from the literature. A methodology has been developed for obtaining a surrogate model for DED process. Originality/value This methodology shows how to achieve realistic simulations of DED process and how to construct a surrogate model for further use in optimization loop.

scholarly journals Effects of Powder Feed Rate on Formation of Fully Equiaxed β Grains in Titanium Alloys Fabricated by Directed Energy Deposition

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 521 ◽  
Author(s):  
Qiang Zhang ◽  
Siyu Zhang ◽  
Min Zheng ◽  
Yongchao Ou ◽  
Shang Sui ◽  
...  
Keyword(s):  
Feed Rate ◽  
Molten Pool ◽  
Cellular Structure ◽  
Energy Deposition ◽  
Grain Morphology ◽  
Thermal Conditions ◽  
Powder Feed Rate ◽  
Powder Feed ◽  
Directed Energy Deposition ◽  
Directed Energy

A near β titanium alloy, Ti5Al2Sn2Zr4Mo4Cr, was fabricated by directed energy deposition (DED) with different powder feed rates to investigate the formation of fully equiaxed β grains. A two-dimensional numerical model was developed to investigate the thermal conditions of the molten pool. Experimental results showed that the formation of an epitaxial cellular structure at the bottom of the molten pool is almost unavoidable. An increase in the powder feed rate produces a moderate thermal condition and promotes the formation of equiaxed grains in a single cladding layer. However, it could not guarantee the formation of a fully equiaxed microstructure in a block sample. From a low to high powder feed rate, fully columnar, mixed equiaxed–columnar, and fully equiaxed microstructures were obtained. Grain morphology was also affected by the remolten process. Increasing the powder feed rate reduced the remolten depth and broke the continuity of the epitaxial cellular structure, leading to different grain morphologies.

scholarly journals Investigation of hybrid manufacturing of stainless steel 316L components using direct energy deposition

2020 ◽  
pp. 095440542094936 ◽  
Author(s):  
Nikolaos Tapoglou ◽  
Joseph Clulow
Keyword(s):  
Stainless Steel ◽  
Energy Deposition ◽  
Hybrid Manufacturing ◽  
Stainless Steel 316L ◽  
Direct Energy Deposition ◽  
Direct Energy ◽  
Finish Machine ◽  
Metallic Parts ◽  
Non Destructive

Direct energy deposition has been established as one of the methods for additive manufacturing metallic parts. The combination of direct energy deposition capabilities with traditional machining centre capabilities has enabled over the past few years the creation of hybrid manufacturing cells that are able to additively manufacture and finish machine components under one platform. This article investigates the production of geometries using a hybrid, additive and subtractive approach. The parameters for depositing stainless steel 316L are initially investigated followed by an assessment of machinability of the additively manufactured material. Finally, the quality of the deposited and machined material was thoroughly examined with a series of destructive and non-destructive methods.

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