MRF (image) World Scientific Share Print E-Mail Caption As the fragmented nano-diamond had a high hardness, the MRF on the surface of the ball during friction was not stable. Moreover, as the duration and the role of the load increased, pit and debris appeared on the ball surface. As the nano-diamond was lower-sized, additional nano-diamond and debris went into the pit and continued to further polish the surface, whereas the depth and diameter of the wear spot became higher. The steel balls rotation produced higher friction and the four-ball test machine detected a higher friction coefficient; consequently, the friction coefficient curve produced a peak. The wall shape change affected the magnetic field strength distribution, whereas the researchers discovered that the deeper groove with the higher the magnetic field strength. At this time, the ferromagnetic particles became a longer solid chain and because the wall was no longer smooth, the friction between the magnetic chain and the wall became higher. This led in the exhibition of a high shear yield strength. Credit Dr Mingmei Zhao Usage Restrictions Use of image should be accompanied by source acknowledgement. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.