LAUSR

ABSTRACT Pulsating water jet technology for rock erosion application has been emphasized in this study. The erosion phenomena are explored as an eroded depth, eroded width and volume eroded of the sandstone at frequency f = 20,000–40,000 Hz by using pulsed water jet. The surface was eroded at pressure 20–40 MPa; standoff distance 20 mm; nozzle diameter 1.6 mm; and feed rate of the jet 125–200 mm/s. The eroded depth, eroded width, and volume of the eroded sections were evaluated through non-contact-type optical profilometer. The result shows the relationship between feed rate of the jet, pressure, and standoff distance, which affects the erosion depth and width and volume removal. At f = 40,000 Hz, the maximum value of erosion depth, width, and volume removal was obtained. The microstructural analysis Field Emission Scanning Electron Microscopy (FESEM) examined the erosion topography, plastic deformation, and failure analysis at a frequency f = 20,000–40,000 Hz. The results reveal that the frequency change affects the erosion, and failure was observed at 40,000 Hz. This is the result of the deeper and narrow eroded surface caused by the enhanced number of impacts (200–320 impact per mm) and concentrated stream of a jet at 40,000 Hz.