Liquid impact erosion of single-crystal magnesium oxide

摘要

The erosion of single-crystal magnesium oxide (MgO) by liquid impact is investigated using controlled liquid jet impacts produced by the Cavendish Laboratory's multiple impact jet apparatus (MIJA). The paper discusses the theoretical modelling of damage threshold curves which allows the investigation of the effect of changes in the damage threshold velocity (DTV) by changing material parameters such as flaw size, fracture stress, and fracture toughness. A model simulating the properties of single-crystal MgO is compared with exeerimental data using MIJA An attraction of using single-crystal MgO is that its cleavage and slip planes are well characterised and dislocation etching techniques are established. The early stages of deformation and fracture above the DTV are described. Comparison is made with erosion data of other infra-red transmitting materials.