5.3 Coating Durability Test
5.3.1 Instruments and Materials
a) A funnel with a cone angle of 60 °, a pin length of 50mm, and a pin inner diameter of (5.5 ± 0.1) mm;
b) Diamond sand (36 "or 46" green silicon carbide)  
Note: The usage of diamond sand is limited to 300 times
5.3.2 Methods and Steps
5.3.2.1 Construct a coating durability test device according to Figure 1, adjust the amount of diamond sand falling to (450 ± 10) g/min, and the distance from the sand dropping port of the funnel switch plate to the sample is 250mm.