Pure Titanium Powder Printing Molding And Block Surface Modification

Titanium alloy has excellent mechanical properties,excellent corrosion resistance and high biocompatibility,which makes it have excellent application prospects in the fields of chemistry,biomedicine,aerospace and automotive industry.Especially with the growth of energy demand and the development of environmental protection,lightweight titanium alloy becomes more and more important.However,in some special applications,the specific stiffness and wear resistance of titanium and its alloys are low,which can not fully meet the requirements of this kind of working conditions,which limits its wider application.In order to effectively solve the problem of insufficient specific stiffness and hardness of titanium and its alloys,and further give full play to the application advantages of titanium and its alloys in various fields,titanium and its alloys can be used in conventional friction and wear environment.Based on pure titanium,the preparation of selective laser melting（SLM）titanium matrix composites and the surface modification experiments of electron beam remelting titanium alloy were carried out respectively.The properties of several typical ceramic particle reinforced phases and related matrix and corresponding intermetallic compounds were calculated and compared through the first principle calculation method The properties of the modified coating and titanium matrix composites were estimated by the equilibrium lattice constant,mechanical properties and electronic structure of Ti C reinforcement.The titanium matrix composites and the corresponding coatings were designed.According to the calculation results,Ti B and Ti C were selected as the ideal reinforcements of titanium matrix composites and surface modified coatings,and the corresponding experiments were carried out.In order to effectively reduce the experimental cost and provide sample performance,we also improved the sample according to the previous research of the research group.In order to reduce the preparation cost of titanium matrix composites in SLM process,low-cost and irregular shaped hydrogenated dehydrogenated titanium（HDH-Ti）and Ti B₂ powder were selected as raw materials.The morphology and composition of the powder were improved by high-energy ball milling and successfully used in SLM process.Ti-Ti B composites prepared by selective laser melting with different Ti B2 addition were prepared.In addition,in order to solve the problems of low density,weak adhesion,easy to cause powder splashing and introduce impurities,easy to produce pore inclusion defects,etc.in the traditional surface powder laying method as a prefabricated cladding material,the above problems are solved by placing Ti C ceramic particles in the nickel base pre coating and synthesizing Ni-Ti C composite coating on the surface of commercial pure titanium by electron beam remelting method,At the same time,the uniform distribution of ceramic particle reinforcement in the coating can also be achieved.Different process parameters were used to irradiate and remelt the surface pre coating with electron beam,and the influence of process parameters on the surface modification of electron beam remelting was explored.Finally,the corresponding mechanical properties of the samples obtained by the two methods are tested and analyzed to verify the feasibility of the two strengthening methods and their strengthening effect on the mechanical properties of the substrate;The microstructure of the sample is analyzed by corresponding technical means,and the strengthening mechanism and specific strengthening methods of the two methods on the mechanical properties of titanium matrix are explored by analyzing the distribution of microstructure in the sample and the changes between different phases,so as to provide a complete set of methods from theoretical analysis to experimental research for the performance improvement of titanium and its alloy.