Study On The Process And Preparation Of NiTi Alloy And Co-Cr-Mo Alloy Medical Implant Materials Based On3D Printing Mound Design

Background:For the past few years, with the development of3D printing, it has become more and more mature and been employed preliminarily in clinic. NiTi alloy and Co-Cr-Mo alloy, as two kinds of safe materials for medical implant has been applied in clinic for many years. However, Medical implants produced directly by3D printing have some disadvantages including complex technology, high cost and low efficiency.Purpose:3D printing is combined with SHS technology and investment casting to develop a set of Digital Manufacturing technology of implanted part with low cost and high efficiency including human body picture gathering,3-dimentional image processing, mold design and polyethylene mold shaping by3D printing, implant material preparation by SHS and investment casting shaping method. The property of Medical implant alloy made by this method was study to help exploit a new way to prepare medical implant part with3D printing technology.Method:1.CT image was generated by scanning human body in Aquilion One TSX-301A CT machine of XiangYa Hospital. Part of bone joint picture was cut out and disposed by Mimics10.0software and corresponding mold image files for3D printing was designed. Our purpose is to study technological parameters of the design flow of the product and printing flow of the mold.2. High precision polyethylene molds were produced by3D printing machine according the image file designed before and was manufacture into reverse mould. Ni powders and Ti powders mixed with a certain proportion were pressed into compaction using different pressure and synthesized porous materials by SHS. The relation between some indexes including Elasticity modulus, strength, interspaces size and porosity and compaction pressure as well as sintering method was investigated systematically.3. Polyethylene mould printed by3D printing machine was used for lost form and the mould produced by3D printing machine was processed into traditional petrolin lost form. Dump box moulding method for ethyl silicate was employed to prepare Co-Cr-Mo alloy transplant in high frequency vacuum induction stove and a series of parameters from appearance to mechanical behavior.Results:1.It would be more simple to collect,process and design3D printing file which can be used to produce certain materials in clinical work and a kind of feasible,simple operational approach was found through a series of post-processing methods summed up from CT technology and computer software in this study. 2. The cylindrical3D printing mould was used to compact the mixture of Ni powders and Ti powders. A series of indexes including elasticity modulus, tensile strength of NiTi alloy prepared by SHS can meet the requirement of bone transplant materials which can be employed in preparing regular shaping transplant metals.3. The mechanical properties and microstructures of Co-Cr-Mo alloy synthesized in polyethylene lost form has no obviously difference with the one in traditional paraffins lost form and has more simple technology. Various kinds of complex medical transplant equipment can be manufactured by this method to meet the requirements of medical transplants particularly for human bone transplant materials.A whole set of inexpensive and efficient techniques for medical NiTi alloy and Co-Cr-Mo alloy based on3D printing technology has been put forward. Experiment results indicate that the workpiece can meet the need of medical implants material special for replacing bone material.