초록 열기/닫기 버튼
The friction behaviors of bulk amorphous thermal spray coating (BAC) and second phase-reinforcedcomposite coatings using a high velocity oxy-fuel spraying process were investigated using a ball-on-disk testrig that slides against a ceramic ball in an atmospheric environment. The surface temperatures were measuredusing an infrared thermometer installed 50 mm from the contact surface. The crystallinities of the coating layerswere determined using X-ray diffraction. The morphologies of the coating layers and worn surfaces wereobserved using a scanning electron microscope and energy-dispersive spectroscopy. The results show that thefriction behavior of the monolithic amorphous coating was sensitive to the testing conditions. Under lower thannormal loads, a low and stable friction coefficient of about 0.1 was observed, whereas under a higher relativeload, a high and unstable friction coefficient of greater than 0.3 was obtained with an instant temperatureincrease. For the composite coatings, a sudden increase in friction coefficient did not occur, i.e., the transitionregion did not exist and during the friction test, a gradual increase occurred only after a significant delay. TheBAC morphology observations indicate that viscous plastic flow was generated with low loads, but severe surfacedamage (i.e., tearing) occurred at high loads. For composite coatings, a relatively smooth surface wasobserved on the worn surface for all applied loads.
키워드열기/닫기 버튼
amorphous thermal spray coating, amorphous metallic matrix composite, friction characteristic, sliding interface temperature
