The Properties Researches And The Theoretical Calculations Of The Dental Materials Ti-Zr/Cu Base Alloys

At present, dental implants become a new way to repair the missing tooth for patients in clinical. There are two parts included in the dental implants. They are the lower body implants (implants) and the upper teeth restorations (dental prosthesis). The implants are direct-long-term contact materials, there are three requirements:first, the modulus must be close to the modulus of human bones; second, corrosion resistance of the materials in the human body physiological environment should be good; the last one, the materials should be biocompatibility. Titanium and titanium alloys possess excellent mechanical properties, strong corrosion resistance and good biocompatibility. The research of titanium alloys is important and meaningful. In the present study, the elements Nb, Sn and Mo were introduced into Ti-Zr alloys, to form the Ti-2Zr-xNb-xSn (x=0,0.1,0.2,0.3) and Ti-2Zr-xNb-xMo (x=0,0.1,0.2,0.3) systems. Physical properties and chemical properties of these two systems were systematic study. The structural, elastic and electronic properties of eight intermetallics in the Ti-Cu-Me (Me=Al, Ga and In) systems are investigated by means of the first-principles method. The main research content is as follows:(1) XRD, metallographic microscope, universal material testing machine and the electrochemical workstation were used to discuss the physical and chemical properties for Ti-2Zr-xNb-xSn (x=0,0.1,0.2,0.3) and Ti-2Zr-xNb-xMo (x=0,0.1,0.2,0.3) systems. The phase composition, compressive strength, yield strength, Young’s modulus and the open circuit potential, corrosion potential and corrosion current performance were tested. The results showed that Ti-2Zr-xNb-xSn (x=0,0.1,0.2,0.3) alloys have more excellent mechanical properties and corrosion resistant performance. When x=0.1, the elastic modulus of the Ti-2Zr-0.1Nb-0.1Sn alloy is14.72GPa, hardness is24.17(HRC60). Corrosion resistance performance of the Ti-2Zr-0.1Nb-0.1Sn alloy is better than the other alloys. The elastic modulus of this alloy is close to the natural bones and has excellent corrosion resistance and comprehensive mechanical properties. Considering the comprehensive results, Ti-2Zr-0.1Nb-0.1Sn alloy is a good choice for dental implanted materials.(2) The structural, elastic and electronic properties of eight intermetallics in the Ti-Cu-Me (Me=Al,Ga and In) systems are investigated by means of the first-principles method. The intermetallics are classified as stable and metastable types in the investigation. The stable phases are those presented in the equilibrium phase diagram at room temperature. The metastable phases are those usually appear in the equilibrium phase diagram at higher temperature. The calculations are performed within the generalized gradient approximation (GGA) to the density functional theory (DFT) using the supercell (SC) method. Calculation results show that the SC approximation is accurate at the zero pressure. The values of calculations show that the TiCuAl, Ti2CuAl5and TiCu2In compounds should be classified to be brittle, and the Tio.5CuAl0.5,TiCu2Al, TiCuGa, Ti2CuGa5and Tio.5CuIno.5compounds are ductile at zero pressure.