Cavitation Erosion and Sliding Wear to Assess Carbide Integrity in AISI D2 Tool Steel

Ultrasonic cavitation and ball-on-disk wear tests were conducted in order to assess the carbide integrity in AISI D2 steel specimens with different heat treatments and carbide orientations on the exposed surface. The response of the tested materials under cavitation erosion was clearly distinguishable for each carbide orientation and heat treatment. Particularly, carbide predominant orientation can be successfully associated with the incubation period of cavitation damage. Validity of the cavitation erosion tests as a useful characterization technique in materials with reinforcement phases is discussed based on the small contact areas associated with the microjets generated in the ultrasonic cavitation test. On the other hand, ball-on-disk tests in conjunction with conventional wear analysis (coefficient of friction graph, wear volume) did not provide a clear relationship between research variables. However, by using discrete Fourier analysis from friction coefficient data, it was possible to establish a correlation between integrity of primary carbide, its orientation and matrix hardness.