A NOVEL METHOD FOR QUANTITATIVE DETERMINATION OF ULTRA-LOW WEAR RATES: APPLICATION TO MULTIPHASE AL-SI ALLOYS

摘要

In order to evaluate new materials that are being considered for linerless aluminum blocks such as the Al-Si alloy GM396-1, it is not only important to determine the mechanical properties such as hardness, Young's modulus, and fracture toughness, but it is crucial to elucidate the wear properties. Unfortunately, the usual methods to determine the wear (and hence wear rate), require quite significant material loss and/or substantial wear scars, that require long experimental times, which might not be practically achievable. Over the lifetime of an average car, the change in diameter of a bore surface is on the order of urn/year which translates to nm/hour wear rates. One objective of this project is to directly determine these very low wear rates in simulated testing conditions that mimic the desired engine environment; i.e. accelerated testing is not possible because of the ubiquity of wear-rate transitions.