VISUALIZATION OF THE ABRASIVE-WATERJET CUTTING PROCESS

Cutting with abrasive waterjets was visualized in three types of materials: Lexan, Lucite and glass. Movie cameras were used at speeds of 64 and 1000 frames/s to record sequences of the jet penetration in these materials. It was found that the cutting process consists of two basic modes of erosion. The first, known as the cutting-wear mode, occurs at relatively shallow angles of impact. This mode results in a steady-state jet-solid interface. The other mode, the deformation-wear mode, occurs at large angles of impact and results in an unsteady penetration zone. The relative contribution of each of these two modes or mechanisms to material removal depends on the process parameters. The cutting process is cyclic in nature when the deformation-wear mechanism is partially or totally contributing to cutting. Qualitative and quantitative results of these visualization experiments suggest a mechanistic model for the penetration process.