Testing methodology for measuring transthickness tensile strength for ceramic matrix composites

This paper discusses experimental methods and test results from a program established to evaluate the transthickness tensile strength of ceramic matrix composites (CMC). Experimental techniques discussed include adhesives, test specimen design, gripping, and fixturing. Testing apparatus and testing protocol are addressed. In addition to addressing experimental techniques, two studies were conducted. The first study investigated the effect of test specimen geometry using circular and square cross section test specimens. The circular button type test specimens were 19 mm in diameter, while the square test specimens were 16.8 mm on a side. Analysis of the test results revealed no statistically significant difference between the two test specimen geometries. The second study involved a mini-round-robin test program undertaken to evaluate a draft test standard and to evaluate the accuracy of the test method. In addition, transthickness tensile strength results from several different CMCs are presented. An attempt is made to correlate between the measured transthickness tensile strength and the varying CMC microstructures investigated.