Ahsan, M. Naveed and Pinkerton, Andrew J. and Moat, Richard J. and Shackleton, Judith (2011) A comparative study of laser direct metal deposition characteristics using gas and plasma-atomized Ti-6Al-4V powders. Materials Science and Engineering: A, 528 (25-26). pp. 7648-7657. ISSN 0921-5093Full text not available from this repository.
This research presents a comparative study of the characteristics of laser direct metal deposition (LDMD) using two types of Ti-6Al-4V powder. Ti-6Al-4V powders prepared using the gas-atomization (GA) and the plasma rotating electrode (PREP) processes were first analyzed using laser diffraction, scanning electron microscopy and micro computed tomography. A 1.5 kW diode laser with a coaxial deposition head was then used to deposit a number of thin-wall structures at a range of processing parameters from each of the powders. The deposited structures were characterized using optical microscopy, scanning electron microscopy. X-ray diffraction and micro computed tomography (MicroCT). The results show some potential benefits of using PREP powder in laser direct metal deposition. PREP powder has a higher deposition rate and deposits show lower intralayer porosity and lower surface roughness. In both cases, deposits of Ti-6Al-4V exhibit a unique epitaxial prior beta grains microstructure that transforms to alpha lathes and retained beta during cooling. X-ray diffraction results show that the overall microstructure is alpha + beta and not martensitic. The lamellar alpha + beta phase spacing (S alpha+beta) increases with laser power but seems unaffected by variation in the mass flow rate of the powder. Micro hardness of the laser deposited Ti-6Al-4V is dependent on the lamellar alpha + beta phase spacing (S alpha+beta) and PREP powder deposits show lower micro hardness than GA powder deposits. (C) 2011 Elsevier B.V. All rights reserved.
|Journal or Publication Title:||Materials Science and Engineering: A|
|Uncontrolled Keywords:||Laser direct metal deposition ; Micro computed tomography ; PREP powder ; Microstructure ; Micro hardness|
|Subjects:||T Technology > TA Engineering (General). Civil engineering (General)|
|Departments:||Faculty of Science and Technology > Engineering|
|Deposited On:||26 Oct 2012 15:10|
|Last Modified:||01 Nov 2012 11:11|
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