Functionally-graded materials and the engineering of tribological resistance at surfaces

Abstract

An article is provided that is highly resistant to localized normal indentation, or indentation tensile stresses, against its surface. The article is a stacked array of at least five layer units each having local anisotropy in at least one direction. Each unit has an adjacent unit that differs in a mechanical property, or offset in principle axis of anisotropy by less than 45°. The article forms part of a construction constructed and positioned to withstand indentation, or contact damage, detrimental to its use having a component normal to any tangent of the surface. The article can be a stacked array of fiber-reinforced polymeric material, i.e., prepreg, with the fiber direction offset from each layer to the next by less than 45°. Methods of making the article and methods of use of the article to resist impact are provided. Also provided are articles having surfaces, the surfaces being constructed and arranged to withstand sliding contact stress. The surfaces of these articles are functionally-graded.

Dependencies are inferred from the claim text.