2.2. Test Apparatus
Figure 1 shows the schematic diagram of erosion test rig confirming to ASTM G 76.The set up was capable of creating reproducible erosive situations for assessing erosion wear resistance of the prepared composite samples. The erosion tester consists of an air compressor, an air particle mixing chamber and accelerating chamber. Dry compressed air was mixed with the particles which are fed at constant rate from a sand flow control knob through a convergent brass nozzle of 4 mm internal diameter. These particles impact the specimen which can be held at different angles with respect to the direction of erodent flow using a swivel and an adjustable sample clip. The velocity of the eroding particles was determined using double disc method[9]. In the present study, dry silica sand (spherical) of different particle sizes (350 µm) were used as erodent. The samples were cleaned in acetone, dried and weighed to an accuracy of ± 0.1 mg accuracy using a precision electronic balance. It is then eroded in the test rig for 10 minutes and weighed again to determine the weight loss. The process was repeated till the erosion rate attains a constant value called steady state erosion rate