2017 | AFC ACCOMPLISHMENTS 94 testing and fabricated by General Atomics with the tri-axially braided Hi-Nicalon™Type S fibers, nominally 150 nm pyrocarbon interphase, and the chemical vapor-infiltrated SiC matrix. Following the test procedure development and completion of the lead test led by Dr. Singh at Oak Ridge National Laboratory (Figure 1), a large number of test specimens were tested by seven member laboratories of ASTM Committee C28 on Advanced Ceramics.The participating labora- tories include NASA Glenn Research Center, Southern Research Institute, General Atomics,Westinghouse Electric Company, UnitedTechnology Research Center, and General Electric. The data sets (Figure 2) show reasonable consistency across the laboratories, verifying that the current C1773-13 ASTM standard is adequate for testing ceramic fiber reinforced ceramic matrix composite tubular specimens. Limited statistical variation in the mechanical properties demon- strates the adequate quality of the SiC/ SiC material employed in these tests. The distribution of ultimate tensile strength data was best described with a 2-parameterWeibull distribution with shape and scale parameters of 10.1 and 249.1 MPa, respectively.A lognormal distribution, with log mean and log standard deviation of 4.52 and 0.096, Figure 2. Ultimate Tensile Strength (UTS) and Proportional Limit Stress for each laboratory obtained from interlaboratory round robin testing (Error bar: ±1 Standard deviation about the mean).