scholarly journals Optimization of EI961 steel spheroidization process for subsequent use in additive manufacturing: Effect of plasma treatment on the properties of EI961 powder

2021 ◽  
Vol 60 (1) ◽  
pp. 936-945
Author(s):  
Nikolai Ozerskoi ◽  
Alexey Silin ◽  
Nikolay Razumov ◽  
Anatoly Popovich
Keyword(s):  
Additive Manufacturing ◽  
Plasma Treatment ◽  
Feed Rate ◽  
Inductively Coupled Plasma ◽  
Plasma Temperature ◽  
Spherical Shape ◽  
Maximum Plasma ◽  
Powder Feed Rate ◽  
Inductively Coupled ◽  
Powder Feed

Abstract For use in additive manufacturing (AM), powders that have a spherical shape, high fluidity, and packing density are required. One of the methods for producing spherical powders is spheroidization using inductively coupled plasma. In this work, the powder of steel grade EI961 was used. To obtain the powder for subsequent use in 3D printing, the selection of modes was carried out with the change in various parameters of the unit: different power, powder feed rate to the plasma as well as the height of feed rate. The optimal spheroidization mode is as follows: power of 15 kW, pressure of 1 atm, feed rate height of 0 mm, and powder feed rate of 28 g·min−1. The temperature distribution over the plasma torch cross section was calculated and the maximum plasma temperature was also determined. In addition, the effect of plasma treatment on the granulometric composition, phase composition, and chemical composition was studied.

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.

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.

Preparation of Silica-Doped Poly(Lactic Acid) Composite Hollow Spheres Containing Calcium Carbonates

2006 ◽  
Vol 309-311 ◽  
pp. 457-460 ◽  
Author(s):  
Noriko Miura ◽  
Hirotaka Maeda ◽  
Toshihiro Kasuga
Keyword(s):  
Lactic Acid ◽  
Inductively Coupled Plasma ◽  
Hollow Spheres ◽  
Spherical Shape ◽  
Atomic Emission ◽  
Poly Lactic Acid ◽  
External Diameter ◽  
Calcium Carbonates ◽  
Inductively Coupled ◽  
A Cell

Silica-doped poly(lactic acid) (PLA) composite hollow spheres containing calcium carbonates (Si-CCPC spheres) were prepared using aminopropyltriethoxysilane (APTES) for injectable bone fillers combined with a cell-delivery system. Si-CCPC spheres have a hollow spherical shape of ~1 mm in the external diameter and an open channel in the shell, which is selfformed. The channel size is about 500 *m in diameter. X-ray energy dispersive spectroscopy (EDS) analysis showed incorporation of silicon in Si-CCPC spheres. After soaking Si-CCPC spheres in simulated body fluid (SBF), hydroxycarbonate apatite formed on the Si-CCPC spheres. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) showed that the Si4+ ion is released from Si-CCPC spheres in SBF.

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