A1 Principle of the method
This method is to test the impact performance of the ball through impact grinding of alumina ball in a polyurethane jar under specified conditions, and to express the wear resistance of alumina ball by unit time wear loss.
A2 Grinding jar
The grinding jar is polyurethane material. The inner diameter is 200mm and the length is 220mm.
A3 Testing machine
Grinding jar can load with 4kg alumina balls and 4L water, and run continuously at 80r/min.
A4 Alumina ball sample preparation
Prepare 4kg alumina ball sample with qualified appearance and size and 4L water, put it into the A2 grinding jar, and grind at 80r/min for 2 hours. After grinding jar stop, take out the alumina ball, wash and dry it for use.
A5 Test Procedure
1. The alumina ball sample processed according to step A4 is weighed as m1 with a balance(accuracy is 1g) .
2. Put above alumina ball sample into the A2 grinding jar, add 4L water, seal tightly the grinding jar, and make the grinding jar rotate at 80r/min for 24 hours and then stop.
3. Take the alumina ball sample out of the grinding jar, wash and dry. Weigh the alumina ball again as m2.
4. Measure the average diameter of 10 piece balls, and name as D.
After the impact and wear test, if there is no crack and damage in alumina ball, it is regarded as qualified for impact resistance.
In the formula: EWT—– equivalent wear and tear (wear loss)-‰;
K—correction coefficient, 4.17×10ˉ4, mmˉ1;
D—the average diameter of the alumina ball, mm;
m1—the total weight of the alumina ball before grinding from A5.1, g;
m2—the total weight of the alumina ball after grinding from A5.3, g;
Post time: Oct-28-2022