scholarly journals SCANNING SPEED INFLUENCE ON THE PHYSICAL PROPERTIES OF LASER METAL DEPOSITION TITANIUM ALLOY

2016 ◽  
Vol 36 (1) ◽  
pp. 132-137
Author(s):  
RM Mahamood ◽  
JO Aweda ◽  
KR Ajao ◽  
S AbdulKareem ◽  
HA Ajimotokan
Keyword(s):  
Titanium Alloy ◽  
Flow Rate ◽  
Gas Flow ◽  
Scanning Speed ◽  
Metal Deposition ◽  
Utilization Efficiency ◽  
Laser Metal Deposition ◽  
Processing Parameter ◽  
Titanium Alloy Ti6al4v ◽  
Deposition Height

The most commonly used aerospace titanium alloy, Ti6Al4V, was deposited on Ti6Al4V plate of dimension 72 x 72 x5mm. The laser power of 3 kW, powder flow rate of 1.44 g/min and gas flow rate of 4 l/min were used throughout the deposition process. The transverse/ scanning speed was varied between 0.005 to 0.095 m/sec according to established result of the preliminary study that produces full dense and pore free deposits. The mass of the deposited powder was obtained by weighing the substrate before the deposition and reweighing after the deposition. The substrate and the deposits were thoroughly cleaned using wire brush and acetone to remove unmelted powder particles from the surface of the substrate and the deposit. The height and width of the deposits were measured with Venier Caliper and the material efficiencies were determined using developed equations. The objective of this research is to determine the influence of the scanning speed on the material efficiency and deposit height in laser metal deposition of titanium alloy- Ti6Al4V. The results of this study showed that, for the set of processing parameter used in this study, the optimum scanning speed was at 0.015 m/sec with the optimum material utilization efficiency of 83.33% and the deposition height of 1.09 mm.  http://dx.doi.org/10.4314/njt.v36i1.17

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.

Laser Metal Deposition of Titanium Alloy (Ti6Al4V): A Review

2019 ◽  
Author(s):  
Esther T. Akinlabi ◽  
Yasuhiro Okamoto ◽  
Martin Ruthandi Maina ◽  
Stephen A. Akinlabi ◽  
Sisa Pityana ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Titanium Alloy Ti6al4v

Variable Powder Flow Rate Control in Laser Metal Deposition Processes

2008 ◽  
Author(s):  
Lie Tang ◽  
Jianzhong Ruan ◽  
Robert G. Landers ◽  
Frank Liou
Keyword(s):  
Transport System ◽  
Flow Rate ◽  
Rate Control ◽  
Metal Deposition ◽  
Powder Flow ◽  
Laser Metal Deposition ◽  
Motion System ◽  
Powder Flow Rate ◽  
Deposition Processes ◽  
Flow Rate Control

This paper proposes a novel method, called Variable Powder Flow Rate Control (VPFRC), for the regulation of powder flow rate in laser metal deposition processes. The idea of VPFRC is to adjust the powder flow rate to maintain a uniform powder deposition per unit length even when disturbances occur (e.g., the motion system accelerates and decelerates). Dynamic models of the powder delivery system motor and the powder transport system (i.e., five–meter pipe, powder dispenser, and cladding head) are constructed. A general tracking controller is then designed to track variable powder flow rate references. Since the powder flow rate at the nozzle exit cannot be directly measured, it is estimated using the powder transport system model. The input to this model is the DC motor rotation speed, which is estimated on–line using a Kalman filter. Experiments are conducted to examine the performance of the proposed control methodology. The experimental results demonstrate that the VPFRC method is successful in maintaining a uniform track morphology, even when the motion system accelerates and decelerates.

scholarly journals Evaluation of the quality of layers applied by LDT laser metal deposition

2018 ◽  
Vol 19 (6) ◽  
pp. 591-596
Author(s):  
Andrzej Mazurkiewicz ◽  
Andrzej Poprzeczka
Keyword(s):  
Heat Affected Zone ◽  
Heat Dissipation ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Cross Sectional ◽  
Weld Overlay ◽  
The Cross

The article presents the results of a study of C45 carbon steel hardfacing using laser metal deposition with Stellit Co-21 powder. The microstructure of the cross-section of samples prepared with different scanning speed and the amount of used powder at constant laser power was observed. Analyzing the cross-sectional areas of the samples, it was found that, at specific production parameters, cracks occur in weld overlay, which should be associated with the amount of heat supplied and discharged, especially at the unheated basis.This may be confirmed by the presence of deposits of weakly branched dendrites in the microstructure, which should be related to the directional heat dissipation process and rapid directional crystallization. It is possible to regulate these phenomena by selecting appropriate processing parameters. The microstructure analysis of cross-sectional areas of samples after hardfacing using LDT technique indicates good metallurgical quality of the deposit with a small heat affected zone of about 660÷760m. The microhardness measurements on the sample cross-sections indicated a wide micohardness distribution ranging from 510HV1 in the weld overlay, about 410HV1 in the heat affected zone, to 270HV1 in the C45 steel base.

Sign in / Sign up

Export Citation Format

Share Document