Thermal shock resistance of additively manufactured alumina

The mechanical behavior and cracking patterns of thermally-shocked additively manufactured alumina were investigated. The flexural strength of test specimens that had been heated to temperatures ranging from 200°C to 1000°C and then rapidly quenched in water was determined at ambient temperature by four-point bending. Results indicated that the surface cracking patterns had a multifractal structure and that an increase in the thermal shock temperature led to an increase in the density and uniformity of the crack network. Further, the flexural strength results were analyzed with Weibull statistics, where the Weibull moduli for most of the thermal shock conditions tested were found to be statistically indistinguishable. It was also found that a significant decrease (~50%) in flexural strength occurred for heating temperatures ≥300°C. The effect of the manufacturing method on cracking patterns is discussed, as well as the implication of the material behavior for practical applications of these materials.. Authors: Brechtl, Jamieson [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000217394283); Martinez, Marco C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)]; Yoon, Bola [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000260875373); Cesarano, Joseph [Robocasting Enterprises, Albuquerque, NM (United States)]; Lara‐Curzio, Edgar [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000345465701). DOE Contract: AC05-00OR22725; AR0001126. Subjects: 36 MATERIALS SCIENCE; additive manufacturing; alumina; mechanical properties; multifractal analysis; thermal shock