College - Author 1
College of Engineering
Department - Author 1
Materials Engineering Department
Degree Name - Author 1
BS in Materials Engineering
College - Author 2
College of Engineering
Department - Author 2
Materials Engineering Department
Degree - Author 2
BS in Materials Engineering
Date
6-2022
Primary Advisor
Blair London, College of Engineering, Materials Engineering Department
Abstract/Summary
Tensile testing and fracture toughness testing were conducted to establish a numerical relationship between interstitial content and performance in forged Ti-6Al-4V. The value of oxygen equivalence was used to represent the interstitial content by combining the weight percent of oxygen, carbon, and nitrogen. The correlation between oxygen equivalence and mechanical properties can be used to accurately predict the performance of forged parts. Samples of forged parts with varying levels of interstitial content were subjected to a recrystallization anneal at 75 F below the beta transus temperature to decrease microstructure variability across parts with a second anneal at 1300 F to relieve residual stress. There was an increase in tensile strength with oxygen equivalence, but the numerical correlation could not be found due to lack of fit. There was a high amount of variation within the data for compositions A and B. The variation in tensile strength for compositions C-F is unknown because only one sample was tested from each composition. Specimen direction (longitudinal vs. transverse) was found to be insignificant for tensile strength. Fracture toughness was on average 11.4 ksi*in^0.5 higher in the L-T direction as compared to the T-L direction. The numerical effect of oxygen equivalence on fracture toughness was inconclusive due to the small data set.
URL: https://digitalcommons.calpoly.edu/matesp/251