A method and model for deposition of Ti-6Al-4V with controlled porosity

Abstract

The use of porous engineered materials is gaining popularity in biomedical implant manufacture due to its capability to promote increased osseointegration and cell proliferation. A method to produce such parts is laser direct metal deposition (LDMD) - a rapid manufacturing technique that has much flexibility. In this work, a 1.5 kW high power diode laser with coaxial powder feed nozzle has been used to manufacture a number of porous multilayer structures from titanium alloy, Ti-6Al-4V. It is found that by optimizing the deposited track geometry and track offset distance, the overall porosity of the structure and pore size can be controlled. Micro computed topography (MicroCT) has been used to examine the internal morphology of the porous structures. An analytical model for direct laser deposition to account for the interaction of multiple tracks in a porous structure has also been developed and is shown to realistically model the multiple layer deposition process.The use of porous engineered materials is gaining popularity in biomedical implant manufacture due to its capability to promote increased osseointegration and cell proliferation. A method to produce such parts is laser direct metal deposition (LDMD) - a rapid manufacturing technique that has much flexibility. In this work, a 1.5 kW high power diode laser with coaxial powder feed nozzle has been used to manufacture a number of porous multilayer structures from titanium alloy, Ti-6Al-4V. It is found that by optimizing the deposited track geometry and track offset distance, the overall porosity of the structure and pore size can be controlled. Micro computed topography (MicroCT) has been used to examine the internal morphology of the porous structures. An analytical model for direct laser deposition to account for the interaction of multiple tracks in a porous structure has also been developed and is shown to realistically model the multiple layer deposition process.