title: Mechanical properties and microstructures of cast Ti-Cu alloys.
abstract: OBJECTIVE
  This study evaluated the mechanical properties of cast Ti-Cu alloys with the hope of developing an alloy for dental casting with better mechanical properties than unalloyed titanium.
  
  
  METHODS
  Ti-Cu alloys with five concentrations of copper (0.5, 1.0, 2.0, 5.0 and 10.0 mass%) were made in an argon-arc melting furnace. The alloys were cast into magnesia-based molds using a centrifugal casting machine. The microstructure, microhardness profile of the specimen cross section, tensile strength, yield strength, and elongation were determined for the castings. Scanning electron microscope fractography was undertaken for the fractured surfaces after tensile testing. XRD was performed on the polished specimens. Results were analyzed using one-way ANOVA and the Student-Newman-Keuls tests.
  
  
  RESULTS
  The mean tensile strengths of all the cast Ti-Cu alloys were significantly (p<0.05) higher than for cast commercially pure titanium (CP Ti). Of the Ti-Cu alloys tested, the 5 and 10% Cu alloys had significantly higher strength than the rest. The 10% Cu alloy exhibited the lowest mean elongation. CP Ti and the 0.5 and 1% Cu alloys showed higher ductility. The bulk hardness of all the cast Ti-Cu alloys, except for the 10% Cu alloy, and CP Ti was approximately the same.
  
  
  CONCLUSIONS
  By alloying with copper, the cast titanium became stronger. Increases in the tensile strength (30%) and yield strength (40%) over CP Ti were obtained for the 5% Cu alloy. Elongation was approximately 3%, which was similar to cast Ti-6Al-4V. Ti-Cu alloys, such as the 5% Cu alloy, could be used for prosthetic dental applications if other properties necessary for dental castings are obtained.
authors.affiliation: Division of Dental Biomaterials, Department of Oral Rehabilitation and Materials Science, Graduate School of Dentistry, Tohoku University, 4-1 Seiryomachi, Aoba-ku, 980-8575, Sendai, Japan. kikuchi@mail.cc.tohoku.ac.jp
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Yukyo
authors.initials: Y
authors.lastname: Takada
authors.forename: Seigo
authors.initials: S
authors.lastname: Kiyosue
authors.forename: Masanobu
authors.initials: M
authors.lastname: Yoda
authors.forename: Margaret
authors.initials: M
authors.lastname: Woldu
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Cai
authors.forename: Osamu
authors.initials: O
authors.lastname: Okuno
authors.forename: Toru
authors.initials: T
authors.lastname: Okabe
mesh_terms: D003300:Copper / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry*; D003734:Dental Casting Investment / Q000737:chemistry*; D003735:Dental Casting Technique; D004548:Elasticity; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D018583:Pliability; D013499:Surface Properties; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D003722:Dental Alloys; D003734:Dental Casting Investment; D003300:Copper; D014025:Titanium