IADR Abstract Archives

Fatigue Testing Of Electron Beam Melted Ti-6Al-4V ELI Alloy

Objectives: The aim of this study was to test the hypothesis that fatigue strength of electron beam melted Ti-6Al-4V ELI alloy depends on direction of electron beam orientation. Methods: A novel technique involving use of electron beam melting was used to cast Ti-6Al-4V ELI alloy blocks with dimensions of 60×60×4mm. Rectangular beam specimens having dimensions of 25×4×3mmwere cut from a block such that the electron beam orientation was either parallel or perpendicular to the long axis of specimens. Twelve specimens with parallel orientation were assigned to Group A and 11 specimens with perpendicular orientation to Group B. Specimens were subjected to cyclic fatigue until fracture in four-point flexure in air using various stress amplitudes below the yield stress. ALTA Pro software was used to fit the data to an inverse power law (IPL)-Weibull model and to predict the stress corresponding to failure probability of 5% and 63% at 2M cycles. Results: Both groups showed approximately the same Weibull modulus, m. Group A showed significantly higher fatigue strength than group B for 63% failure probability, but there was no significant difference in fatigue strength in both groups for 5% failure probability. Estimated fatigue strengths with 95% confidence intervals and IPL-Weibull parameters K, n and m can be summarized as follows.

Group A

Group B

-ln K

37.7

39.8

n

4.43

5.19

m

1.16

1.04

σ (in MPa) for Pf=5% @ 2M cycles

105 (71,140)*

75 (49,104)*

σ (in MPa) for Pf=63% @ 2M cycles

186 (158, 211)*

130 (107,150)*

Pf = Probability of failure by time, t, at stress, σ

*Estimate (95% confidence interval)

Conclusion: Fatigue strength of the material was independent of direction of electron beam orientation at clinical load levels. NIH-NIDCR grants DE017991 and DE013358.


IADR/PER General Session
2010 IADR/PER General Session (Barcelona, Spain)
Barcelona, Spain
2010
213
Dental Materials 8: Metal-based Materials
  • Joshi, Gaurav  ( University of Mississippi Medical Center, Jackson, MS, USA )
  • Duan, Yuanyuan  ( University of Mississippi Medical Center, Jackson, MS, USA )
  • Neidigh, John  ( University of Mississippi Medical Center, Jackson, MS, USA )
  • Griggs, Jason  ( University of Mississippi Medical Center, Jackson, MS, USA )
  • Koike, Mari  ( Baylor College of Dentistry, Dallas, TX, USA )
  • Okabe, Toru  ( Baylor College of Dentistry, Dallas, TX, USA )
  • Chahine, Gilbert  ( Southern Methodist University, Dallas, TX, USA )
  • Kovacevic, Radovan  ( Southern Methodist University, Dallas, TX, USA )
    • Oral Session
    Metals: Mechanical and Physical Properties and Bonding
    07/14/2010