Abstract
It is very important to clarify fracture behavior of the materials under low temperature atmosphere. In this study, we first constructed the experimental fracture apparatus by combining cooling furnace with the method of caustics for investigating fracture behavior of various materials in the temperature range from room temperature to about 93K. Then, fundamental points of applicability of the caustics technique in this experimental system are studied. It is shown that a clear caustic pattern can be observed at very low temperature by using this experimental apparatus. Influences of low temperature on fracture toughness KIC and caustic constant c0 are analyzed for some polymers, glass and ceramic plates by using the experimental apparatus constructed here. Moreover, we tried to measure the value of c0 of ceramics by strain gage technique. There is not so large variation in the value of c0 of ceramics and glass plates within the temperature tested, but the values c0 of polymers are decreased at low temperature. Fracture toughness values KIC of glass, Pyrex glass and PMMA plates become large at low temperature.
