Bioactive ceramic films on titanium substrate are prepared successfully by micro-arc oxidation in electrolyte solution containing NaOH only. The coatings are prepared by micro-arc oxidation at various applied current densities (200-400 mA/cm2) and in NaOH electrolyte with different concentrations. The XRD shows that they are composed of rutile, anatase, Na2Ti6O13, and Na2Ti4O9 phases. The composition and surface morphologies are strongly dependent on the applied current density and electrolyte concentration. For example, at high current density, the phase is mainly composed of rutile and Na2Ti6O13, and at high electrolyte concentration, it is Na2Ti6O13 phase. The morphologies of the samples vary with the increase of current and electrolyte concentration. The apatite-inducing ability of bioactive ceramic films is evaluated in biological model fluids. After soaking in biological model fluids, the titania-based coatings containing Na2Ti6O13 phase have excellent capability of inducing bone-like apatite.

As an innovative machining process for hole-making, helical milling (also known as orbital drilling) presents great potential in machining aircraft structures due to temperature and cutting force reduction, flexible kinematics, and improved borehole quality. Meanwhile, the application of hybrid robot with their high accuracy and better stiffness are increased in aircraft assembly machining operations. Combining these two advanced technologies, this paper focuses primarily on the investigation of the TriMule hybrid robot elastic deformation during helical milling hole-making process and its influence on the diameter error of machined hole. The elastic deformation of series and parallel parts under cutting force condition was investigated by finite element simulation software SAMCEF. The TriMule robot helical milling experiments were also carried out to determine the variation of hole diameter error, and an offline compensation method with modifying the eccentricity at different hole depth was proposed based on the established diameter error model. From experimental verification results, it can be found that the hole diameter error of TriMule robot helical milling can be reduced and the consistency of hole diameter accuracy can be significantly improved by proposed error compensation method.

CaTi(4) (PO(4))(6) coatings was prepared on the surface of CP (commercially pure) Titanium substrate via micro arc oxidation in a newly designed electrolyte system. The preparation method -micro arc oxidation, as well as its discharge characterization was described and studied. The phases, morphology, chemical composition of the coatings were characterized by XRD, EDX and SEM analysis respectively. The results show: the main phase of the prepared coating was CaTi(4) (PO(4))(6) which is a bioactive coating material, the morphology of the coating was rather coarse and not like that of traditional MAO coating which was full of pores. Also the samples prepared in different electrolyte systems were studied and compared.

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