Direct Manufacturing Of Customized Surgery Orienting Model By Selective Laser Melting

Selective laser melting (SLM) is a new technology of Rapid Prototyping (RP) developed in the last ten years. Metal parts can be directly made from powders by SLM, so it became one of the most promising technologies in the field of the advanced manufacturing. Current research of SLM involves the development of equipment, process optimization, and the experiment of application.The research in this thesis was focusing on the medical application of selective laser melting. 316L stainless steel powder which has excellent biocompatibility is used in the experiments. The processing parameters, energy density, relative density, surface profile and characteristics of micro structures of 316 L stainless steel parts which processed by SLM was studied. The application of SLM in medical field especially in design and application of medical implants and surgery orienting model had beeb studied. The main achievements were as follows:Firstly, the application of rapid prototyping in medical area was reviewed. The basic principles and the present research situation of selective laser melting were discussed. These contents stated above provided a theoretical basis to this study.Secondly, a solution for medical application was proposed to manufacture customized surgery model by using selective laser melting combined with reverse engineering. A method of all-digital rapid design and manufacture of metal customized surgical model using reverse-engineering, forward-design and selective laser melting technologies was proposed. The process was demonstrated by taking surgical model of a typical common surgery case, osteonecrosis of the femoral head as examples.An SLM system equipped with fiber laser was employed to study technical parameters, energy density, relative density, surface profile, some frequent processing defects and characteristics of micro structures of 316 L stainless steel parts. Based on analysis of surgical needs, methods to improve the model dimensional accuracy and scanning strategies such as offsetting the scanning lines in two adjacent layers, orthogonal scanning and partition scanning to decreased thermal deformation and undersurface process defects had been figured out. Finally, surgical models which can meet the application requirements was designed and manufactured successfully.Finally, some typical surgery cases were studied, and a systematic solution of all-digital customized surgery was proposed. From CT/MRI image data of a patient preoperative planning, surgical simulation and design the customized surgery model can be completed. The technology of direct manufacturing of surgery orienting model by selective laser melting shows obvious superiority with high speed, precise profile and good accuracy in size comparing with the traditional ones ,and will build a foundation for more clinical applications in the future.