Topic：Design and Manufacture of Complex Titanium Scaffolds using Selective Laser Melting

Speaker：Prof. Tim Sercombe

　　　　  The University of Western Australia

Time: 15:00-17:00 PM, Thurs., Nov. 8, 2012

Venue: Room 406, R&D Center, IMR CAS

Abstract：This seminar will highlight some of our recent work in the design and manufacture of complex titanium scaffolds. The aim of the work is to develop a new generation of bone implants with key biomechanical properties much closer to those of real bone and which can be individually tailored for each patient's needs. The structures will be designed using topology optimization to have a scaffold architecture that not only has modulus matching that of the bone it replaces, but also has been optimized for strength, bone in-growth and bio-transport. These optimized scaffolds will then be created using the latest Selective Laser Melting (SLM) technology from new generation, low-modulus beta titanium alloys. The resultant implants will have significantly improved bio-integration, fixation and hence longevity compared to currently available implants.

Selective Laser Melting (SLM) is an Additive Manufacturing technology, whereby metal powder is melted using a high intensity infrared laser beam that traces the geometry of each layer. Theoretically, parts of almost any geometry can be constructed from any metal powder via SLM. This high degree of flexibility makes SLM the ideal platform for this project. Although SLM has been applied to the manufacture titanium components, this has been limited to the traditional α + β alloys Ti-6Al-4V and Ti-6Al-7Nb. Low-modulus beta titanium alloys comprising non-toxic and non-allergic elements are currently being developed as the next generation metallic implant material. One such alloy is Ti-24Nb-4Zr-8Sn (Ti2448), which has a modulus of ~50 GPa, less than half that of conventional titanium. Complex scaffolds in Ti2448 and Ti-6Al-4V have been manufactured using SLM. The former can be used to produce parts whose stiffness can be tailored to match that of bone, while the latter creates parts with exceptional strength and stiffness to weight ratios.