The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 21, 1998
Filed:
Jul. 05, 1996
Scott A Barnett, Evanston, IL (US);
William D Sproul, Palantine, IL (US);
Ming-show Wong, Northbrook, IL (US);
Xi Chu, Evanston, IL (US);
Northwestern University, Evanston, IL (US);
Abstract
The present invention provides a coated article comprising a substrate that can be non-crystalline or crystalline such as a polycrystalline engineering material, having advantageous mechanical properties and a superlattice-type protective composite coating on the substrate. The composite coating comprises a plurality of vapor deposited, ion bombarded, polycrystalline layers of different adjacent compositions formed one atop the other in lamellar manner. The polycrystalline layers have sufficiently thin individual layer thicknesses (e.g. not exceeding about 150 nanometers) and sufficiently distinct and different compositions proximate their interfaces despite being ion bombarded as to constitute superlattice layers that exhibit a collective hardness exceeding the hardness of any individual layer material in homogenous or bulk form. The composite coating is ion bombarded to an extent that the individual layers are substantially free of intragranular voids without adversely affecting the compositional modulation of the superlattice layers. Moreover, the composite coating can have planar or non-planar interlayer interfaces and still exhibit substantially improved hardness.