Bitte wählen Sie ihr Lieferland und ihre Kundengruppe
Ceramic coatings used in paving must present high abrasion wear resistance. Therefore a method to guarantee a high quality of glazed tiles was presented based on the determination of the Moh's hardness. A correlation between the Mohs hardness measurements and the scratching hardness during the scratching test is presented, so problems of the traditional test arising from little fluctuations in the applied force, attack angle, scratching velocity and the fragmentation of the standards compared with the glazed tile can be eliminated. In this work, the Mohs hardness was evaluated by means of scratching tests. This method provides results that are obtained under controlled conditions, including the applied force, the scratching velocity, the attack angle and the indentor integrity. The groove widths were measured by optical microscopy and the scratch hardness values (Hr) were calculated. From the calculated hardness values the Mohs hardness was evaluated using the relation Mohs hardness = (ln (Hr)-6,72)/0.63. The Mohs hardness values were then measured in five commercial ceramic tiles (three smooth and two rough tiles) to validate the model. In summery, the scratching test or sclerometric test guarantees the control of the applied force, the attack angle, the scratching velocity and the fragmentation of the standards during the test. The scratching test for assessment of the Mohs hardness provides more precise values that the traditional test.