Measuring multi-asperity wear with nanoscale precision

Wear of multi-asperity interfaces remains difficult to predict from first principles, in part because improvements are required in our ability to quantify and track wear across the micro-to nanometer scale. In this work, we developed a 6 degrees of freedom topographical difference method based on large atomic force microscopy (AFM) measurements, up to 90 x 90 mu m(2) in size. We detect wear volumes as small as 1.6 x 10(-11) +/- 3.7 x 10(-12) mm(3) (0.016 mu m(3)), beyond the sensitivity of many existing techniques for the quantification of wear at multi-asperity interfaces. We show that our wear detection technique can be combined with 100 mN normal force ball-on-flat friction experiments to track nanoscale wear across the entire area of apparent contact.

Automated summary

In this work, a 6 degrees of freedom topographical difference method based on large atomic force microscopy (AFM) measurements was developed to detect wear at multi-asperity interfaces. The technique was able to detect wear volumes as small as 1.6 x 10(-11) +/- 3.7 x 10(-12) mm(3) (0.016 mu m(3)), beyond the sensitivity of many existing techniques. It was also combined with 100 mN normal force ball-on-flat friction experiments to track nanoscale wear across the entire area of contact.