TY - GEN

T1 - A comparison of laser additive manufacturing using gas and plasma-atomized Ti-6A1-4V powders

AU - Ahsan, M. Naveed

AU - Pinkerton, Andrew J.

AU - Ali, Laiq

PY - 2012

Y1 - 2012

N2 - This research presents a comparative study of the characteristics of laser additive manufacturing (LAM) using two types of Ti-6A1-4V powder. Ti-6A1-4V powders prepared using the gas-atomization (GA) and the plasma rotating electrode (PREP) processes were first analyzed using laser diffraction, scanning electron microscopy and microcomputed 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 microcomputed tomography (MicroCT). In both cases, deposits of Ti-6A1-4V 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. The lamellar alpha + beta phase spacing (S alpha+beta) increases with laser power but seems unaffected by variation in the powder mass flow rate. Micro hardness of the laser deposited Ti-6A1-4V is dependent on the lamellar a 0 phase spacing (S alpha+beta). The results show some potential benefits of using PREP powder in laser additive manufacturing. PREP powder has a higher deposition rate and deposits show lower intralayer porosity and lower surface roughness. However, PREP powder deposits show lower micro hardness than GA powder deposits.

AB - This research presents a comparative study of the characteristics of laser additive manufacturing (LAM) using two types of Ti-6A1-4V powder. Ti-6A1-4V powders prepared using the gas-atomization (GA) and the plasma rotating electrode (PREP) processes were first analyzed using laser diffraction, scanning electron microscopy and microcomputed 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 microcomputed tomography (MicroCT). In both cases, deposits of Ti-6A1-4V 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. The lamellar alpha + beta phase spacing (S alpha+beta) increases with laser power but seems unaffected by variation in the powder mass flow rate. Micro hardness of the laser deposited Ti-6A1-4V is dependent on the lamellar a 0 phase spacing (S alpha+beta). The results show some potential benefits of using PREP powder in laser additive manufacturing. PREP powder has a higher deposition rate and deposits show lower intralayer porosity and lower surface roughness. However, PREP powder deposits show lower micro hardness than GA powder deposits.

M3 - Conference contribution/Paper

SN - 978-0-415-68418-7

SP - 625

EP - 633

BT - Innovative Developments in Virtual and Physical Prototyping

A2 - Bartolo, PJ

A2 - DeLemos, ACS

A2 - Tojeira, APO

A2 - Pereira, AMH

A2 - Mateus, AJ

A2 - Mendes, ALA

A2 - DosSantos, C

A2 - Freitas, DMF

A2 - Bartolo, HM

A2 - Almeida, HD

A2 - IM, DosReis

A2 - Dias, JR

A2 - Domingos, MAN

A2 - Alves, NMF

A2 - Pereira, RFB

A2 - Patricio, TMF

A2 - Ferreira, TMD

PB - CRC PRESS-TAYLOR & FRANCIS GROUP

CY - Boca Raton

T2 - 5th International Conference on Advanced Research and Rapid Prototyping

Y2 - 28 September 2011 through 1 October 2011

ER -