Commentary on U.S. Army Standard Test Method for Flexural Strength of High Performance Ceramics at Ambient Temperature

The Army recognizes the potential applicability of the new ceramics to such systems as heat engines and missile radomes. One of the major obstacles to the use of ceramic materials as structural entities, devices, or component parts of military end items has been a definite lack of design data. The reliability of design data for ceramics is generally conceded to be of relatively low order as compared with such materials as metals and plastics. Part of this problem can be traced to the lack of standardization of test methods for high performance ceramics. This document was developed as a standard test method which will reduce experimental error and will greatly enhance the reproducibility and consistency of strength data for Army systems. The standard is intended for, but not limited to, usage wtih monolithic ceramics such as alumina, silicon nitride, and silicon carbide. The value of flexural data for design is discussed in this report. Background information and considerations that led to the standard are presented. Keywords mechanical properties metric system bending jigs error analysis.