TY - JOUR

T1 - Porous structures fabrication by continuous and pulsed laser metal deposition for biomedical applications; modelling and experimental investigation

AU - Ahsan, M. Naveed

AU - Paul, Christ P.

AU - Kukreja, L. M.

AU - Pinkerton, Andrew J.

PY - 2011/4/1

Y1 - 2011/4/1

N2 - The use of porous surface structures is gaining popularity in biomedical implant manufacture due to its ability to promote increased osseointegration and cell proliferation. Laser direct metal deposition (LDMD) is a rapid manufacturing technique capable of producing such a structure. In this work LDMD with a diode laser in continuous mode and with a CO2 laser in pulsed modes are used to produce multi-layer porous structures. Gas-atomized Ti-6Al-4V and 316L stainless steel powders are used as the deposition material. The porous structures are compared with respect to their internal geometry, pore size, and part density using a range of techniques including micro-tomography. Results show that the two methods produce radically different internal structures, but in both cases a range of part densities can be produced by varying process parameters such as laser power and powder mass flow rate. Prudent selection of these parameters allows the interconnected pores that are considered most suitable for promoting osseointegration to be obtained. Analytical models of the processes are also developed by using Wolfram Mathematica software to solve interacting, transient heat, temperature and mass flow models. Measured and modelled results are compared and show good agreement. 

AB - The use of porous surface structures is gaining popularity in biomedical implant manufacture due to its ability to promote increased osseointegration and cell proliferation. Laser direct metal deposition (LDMD) is a rapid manufacturing technique capable of producing such a structure. In this work LDMD with a diode laser in continuous mode and with a CO2 laser in pulsed modes are used to produce multi-layer porous structures. Gas-atomized Ti-6Al-4V and 316L stainless steel powders are used as the deposition material. The porous structures are compared with respect to their internal geometry, pore size, and part density using a range of techniques including micro-tomography. Results show that the two methods produce radically different internal structures, but in both cases a range of part densities can be produced by varying process parameters such as laser power and powder mass flow rate. Prudent selection of these parameters allows the interconnected pores that are considered most suitable for promoting osseointegration to be obtained. Analytical models of the processes are also developed by using Wolfram Mathematica software to solve interacting, transient heat, temperature and mass flow models. Measured and modelled results are compared and show good agreement. 

KW - Osseointegration

KW - Laser metal deposition

KW - Surface porous structures

KW - Biomedical implants

KW - Analytical model

U2 - 10.1016/j.jmatprotec.2010.11.014

DO - 10.1016/j.jmatprotec.2010.11.014

M3 - Journal article

VL - 211

SP - 602

EP - 609

JO - Journal of Materials Processing Technology

JF - Journal of Materials Processing Technology

SN - 0924-0136

IS - 4

ER -