Study On Digital Design And Direct Manufacturing Of Customized Implant Based On Selective Laser Melting

Additive manufacturing as a new manufacturing technology is rapidly changing the waywe live. Selective laser melting technology (SLM) is one of the important technologies ofdirect manufacturing metal functional parts in additive manufacturing.By using SLMtechnologies, any complex shape, good mechanical properties and high dimensional accuracyfunctional parts can be obtained. And it is suitable for small quantities, customized complexfunctional parts, moreover especially for patients with customized implant.Current researchon SLM mostly concentrates on materials technology, equipment and specific application case,but relatively little research is on the changes and impact of design of new manufacturingtechnology. In order to take full advantage of customized implant directly manufactured bySLM, researching on customized implant design and manufacturing based on SLM.is verymeaningful.Accordingly, this study is about the design and manufacture of customized implant basedon selective laser melting. Main contents and results are as follows:(1) Study the freedom design rules of selective laser melting. Based on additivemanufacturing common knowledge–concept of "free growth" of structure, derive the designand manufacture of freedom structure. Construct design rule based on the freedom structureof SLM with freedom structure and traditional designs axiom system, and study the structuraldesign constraints-constraints principles, tools constraints, application constraints. Based onthe design rule of SLM freedom structure,discuss the design rules of customized implantsand propose two application constraints withincustomized implant design—the constraints ofshape matching customized, the constraints of performance approximation.（2）Basic design methods of customized implants were studied.under the design rule forSLM free structure, taking the matching of customized geometric shape as constraints, basicstructure of customized implants was designed by using forward and reverse design method.Taking the similarity between structural performance and host tissue as constraint,performance of customized implants was optimized by taking porous structure as performancestructure and by conducting integrated or part combination design with geometric shape. Atthe same time, in order to improve efficiency, reasoning method based on living example wasused. Similar implant was matched to patient first, and then variant design was conducted topart structure, so as to meet requirement of personalization.(3) Based on the theory of melting track accumulation, influencing factors of melting track morphology and influence of intra-layer overlapping and inter-layer overlapping ondensity were studied, so as to set up a research method for material process. Processparameters for high density and continuous density were obtained by studying process of316L stainless steel、CoCrMo、Ti6Al4V. Specimens were manufactured by using processparameters for high density, and then manufacturing performance、corrosion resistance、geometric performance were tested. It is shown that SLM performance of medical metallicmaterial316L stainless steel、CoCrMo、Ti6Al4V are all better than that of casting parts, it canmeet the requirement of medical products.(4) In order to improve responsiveness of design and manufacture for customizedimplants, collaborative design and manufacture method for customized implants were set upbased on networking manufacture. Design and manufacture of customized implants needinformation communication among doctor、designer、manufacturer、analyzer and processorto finish the design and manufacture task of customized implants. In order to design andmanufacture customized implants faster and better, information communication betweenorganizers was completed through collaborative method in design and manufacture task. Thecollaborative process was ensured to go well through personnel organizing control、knowledge control、collaborative perception control、and collaborative collision control, so asto solved the slow response problem of design and manufacture for customized implants.