The effects of ball surface condition in the micro-scale abrasive wear test

The ball-crater micro-scale abrasive wear test can be applied to coated samples and small bulk samples. The surface condition of the ball influences the magnitude and the reproducibility of the measured wear coefficient. Use of a polished new ball in the test may give uncertain or anomalously low wear coefficients, particularly for relatively soft specimens. This effect is explained in terms of the ease of entrainment of abrasive particles into the contact area. Reproducible results are obtained with pre-conditioned balls with slight surface pitting, and the use of such balls is recommended for routine testing.