The Investigation of Gravity-Driven Metal Powder Flow in Coaxial Nozzle for Laser-Aided Direct Metal Deposition Process

2005 ◽  
Vol 128 (2) ◽  
pp. 541-553 ◽  
Author(s):  
Heng Pan ◽  
Todd Sparks ◽  
Yogesh D. Thakar ◽  
Frank Liou
Keyword(s):  
Gas Flow ◽  
Particle Concentration ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Powder Flow ◽  
Shielding Gas ◽  
Two Phase ◽  
Coaxial Nozzle ◽  
Gravity Driven ◽  
Nozzle Geometries

The quality and efficiency of laser-aided direct metal deposition largely depends on the powder stream structure below the nozzle. Numerical modeling of the powder concentration distribution is complex due to the complex phenomena involved in the two-phase turbulence flow. In this paper, the gravity-driven powder flow is studied along with powder properties, nozzle geometries, and shielding gas settings. A 3-D numerical model is introduced to quantitatively predict the powder stream concentration variation in order to facilitate coaxial nozzle design optimizations. Effects of outer shielding gas directions, inner/outer shielding gas flow rate, powder passage directions, and opening width on the structure of the powder stream are systematically studied. An experimental setup is designed to quantitatively measure the particle concentration directly for this process. The numerical simulation results are compared with the experimental data using prototyped coaxial nozzles. The results are found to match and then validate the simulation. This study shows that the particle concentration mode is influenced significantly by nozzle geometries and gas settings.

Experimental and Numerical Analysis of the Powder Flow in a Multi-Channel Coaxial Nozzle of a Direct Metal Deposition System

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Piyush Pant ◽  
Dipankar Chatterjee ◽  
Sudip Kumar Samanta ◽  
Aditya Kumar Lohar
Keyword(s):  
Gas Flow ◽  
Flow Characteristics ◽  
Turbulence Models ◽  
Deposition Process ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Powder Flow ◽  
Coaxial Nozzle ◽  
Proposed Model ◽  
Blown Powder

Abstract The work explores the powder transport process, using numerical simulation to address the dynamics of the powder flow in an in-house built multi-channel coaxial nozzle of a direct metal deposition (DMD) system. The fluid turbulence is handled by the standard k–ɛ and k–ω turbulence models, and the results are compared in order to predict their suitability. An image-based technique using CMOS camera is adopted to determine the powder flow characteristics. The model is validated with the in-house experimental results and verified available results in the literature. The findings of this work confirms the application of the k–ω model for powder gas flow investigations in blown powder additive manufacturing (AM) processes due to its better predictive capability. The proposed model will assist in simulating the direct metal deposition process.

scholarly journals Simulation and experimental research based on carrier gas flow rate on the influence of four-channel coaxial nozzle flow field

2020 ◽  
pp. 002029402096423
Author(s):  
Shi Rui Guo ◽  
Qian Qian Yin ◽  
Lu Jun Cui ◽  
Xiao Lei Li ◽  
Ying Hao Cui ◽  
...  
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Simulation Analysis ◽  
Two Phase ◽  
Carrier Gas ◽  
Coaxial Nozzle ◽  
Convergence Point ◽  
Flow Convergence ◽  
Fluent Software ◽  
Carrier Gas Flow

This paper investigates the influence of carrier gas flow on the external flow field of coaxial powder feeding nozzle. FLUENT software was adopted to establish gas-solid two-phase flow. The simulation of powder stream field under different carrier gas flow was also carried out. Results show that the larger the flow of carrier gas is, the higher the gas flow field velocity at the nozzle outlet is. At the same time, the concentration at the convergence point is lower, and the convergent point is maintained at 0.015 m. Under the condition of 4 L/min, the powder flow convergence is good. When it exceeds 4 L/min, powder spot diameter increases. The experiment of powder aggregation and laser cladding forming were completed, which shows that the forming effect is the best one under the condition of 4 L/min. It is consistent with the simulation analysis results and has a high reference to the optimization of the process parameters of coaxial nozzle.

Effect of Powder Flow Rate and Gas Flow Rate on the Evolving Properties of Deposited Ti6Al4V/Cu Composites

2014 ◽  
Vol 1016 ◽  
pp. 177-182 ◽  
Author(s):  
Mutiu F. Erinosho ◽  
Esther Titilayo Akinlabi ◽  
Sisa Pityana
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Pure Copper ◽  
Metal Deposition ◽  
Powder Flow ◽  
Laser Metal Deposition ◽  
Gas Flow Rate ◽  
Flow Rates ◽  
Powder Flow Rate ◽  
Hardness Values

—Pure copper was deposited with Ti6Al4V alloy via laser metal deposition (LMD) process to produce Ti6Al4V/Cu composites. This paper reports the effect of powder flow rate (PFR) and gas flow rate (GFR) of laser metal deposited Ti6Al4V/Cu composites. The deposited samples were characterised through the evolving microstructure and microhardness. It was observed that the PFR and GFR have an influence on the percentage of porosity present in the samples. The higher the flow rates of the powder and the gas, the higher the degree of porosity and vice versa. The widmanstettan structures were observed to be finer as the flow rate reduces which in turn causes a decrease in the hardness values of the deposited composites. The hardness values varied between HV381.3 ± 60 and HV447.3 ± 49.

Spatial powder flow measurement and efficiency prediction for laser direct metal deposition

2019 ◽  
Vol 362 ◽  
pp. 397-408 ◽  
Author(s):  
Daniel Eisenbarth ◽  
Paulo Matheus Borges Esteves ◽  
Florian Wirth ◽  
Konrad Wegener
Keyword(s):  
Flow Measurement ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Powder Flow

Numerical and Experimental Study of Shielding Gas Orientation Effects on Particle Stream Concentration Mode in Coaxial Laser Aided Material Deposition Process

2004 ◽  
Author(s):  
Heng Pan ◽  
Yogesh D. Thakar ◽  
Frank Liou
Keyword(s):  
Experimental Study ◽  
Gas Flow ◽  
Velocity Ratio ◽  
Deposition Process ◽  
Numerical Approach ◽  
Shielding Gas ◽  
Two Phase ◽  
Powder Concentration ◽  
Turbulence Flow ◽  
Material Deposition

Laser aided deposition quality largely depends on the powder stream structure below the nozzle. Modeling of the powder concentration distribution rarely relies on the numerical approach partially due to the complex phenomenon involved in the two-phase turbulence flow. In this paper, a numerical model is introduced to predict the particle-gas flow precisely and economically in order to meet the practical requirement for coaxial nozzle design optimizations. This model is able to quantitatively predict the powder stream concentration mode under different outer shielding gas directions and inner/outer gas velocity ratio. The numerical simulation results are compared with the experimental study using prototyped coaxial nozzles. The results are found to match. This study shows that the particle concentration mode is influenced significantly by the outer gas direction and gas flow settings.

Process mechanisms based on powder flow spatial distribution in direct metal deposition

2018 ◽  
Vol 254 ◽  
pp. 361-372 ◽  
Author(s):  
Hua Tan ◽  
Weixun Shang ◽  
Fengying Zhang ◽  
Adam T. Clare ◽  
Xin Lin ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Powder Flow
Sign in / Sign up

Export Citation Format

Share Document