Self-organized metal alloys for wear applications

Inactive Publication Date: 2017-08-10
THE BOARD OF TRUSTEES OF THE UNIV OF ILLINOIS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The patent text describes a new type of metallic alloy that contains small amounts of silver (Ag) distributed throughout a matrix of other metals such as nickel (Ni), iron (Fe), copper (Cu), or cobalt (Co). The size of the Ag precipitates is less than about 500 nm. The invention also includes methods for making the alloy and using it to coat substrates. The technical effect of this alloy is that it has improved mechanical properties and can be used in a variety of applications such as electronics, sensors, and optics.

Problems solved by technology

These two main requirements, however, are often conflicting, since many very hard or super hard materials such as oxides, nitrides and carbides are also brittle, and thus have poor toughness.
Conversely, tough materials generally do not possess sufficient hardness.
One important limitation to these traditional approaches, however, is that the wear process itself modifies the microstructure of the coatings, often resulting in a gradual degradation in their performance.
Most of the prior work, however, did not include the re-organization of the material bulk microstructure near the contacting surfaces.

Method used

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  • Self-organized metal alloys for wear applications
  • Self-organized metal alloys for wear applications
  • Self-organized metal alloys for wear applications

Examples

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examples

Fabrication of Alloys

[0046]Unless otherwise specified, the alloys in the examples are prepared as follows. Commercially pure powders (selected from Ag, Ni, Fe and Cu) are combined in the atomic amounts specified and then subjected to high-energy ball milling using a SPEX 8000 mill in an argon glove box for 12 h at ambient temperature (50° C.). Ball milling forces the mixing of matrix and Ag into a nanocomposite. The ball-milled powders are then compacted by warm pressing at 300° C. with a 1 GPa load under high vacuum (1.5×10−8 torr), producing cylinders with density exceeding 99% of the theoretical density. Limited contamination of powders can occur during ball milling by milling tools; e.g., when Fe is the matrix, small Fe2O3-type precipitates can be formed during compaction and annealing. The size and density of these nanoscale precipitates can be measured by Z-contrast imaging. Lastly, hardness is measured by nanoindentation, which is performed by ASTM E2546.

Wear Testing

[0047]Pin...

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Abstract

A two-phase metallic alloy comprising precipitates of Ag possessing a volume-averaged diameter of less than about 500 nm dispersed in a matrix selected from the group consisting of Ni, Fe, combinations of Ni with Cu and combinations of Fe with Cu.

Description

FIELD OF THE INVENTION[0001]The invention relates to self-organized metal alloys for wear applications. More particularly, the invention relates to two-phase metallic alloys having nanometer-size precipitates of Ag dispersed in a matrix of Ni, Fe, Ni and Cu or Fe and Cu.BACKGROUND OF THE INVENTION[0002]High resistance to frictional wear requires that materials in contact: (i) are hard, in order to minimize the damage introduced by high contact stresses; and (ii) possess high toughness, so that despite the accumulation of plastic deformation near the sliding surfaces, the volume of debris generated is small. These two main requirements, however, are often conflicting, since many very hard or super hard materials such as oxides, nitrides and carbides are also brittle, and thus have poor toughness. Conversely, tough materials generally do not possess sufficient hardness. The common approach for solving this dilemma is to use composite materials, which combine high hardness and high tou...

Claims

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Application Information

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IPC IPC(8): C22C30/02B22F3/02C22F1/10C22C19/03C22C1/04B22F9/04B22F3/24
CPCC22C30/02B22F9/04B22F3/02B22F3/24C22C19/03C22C1/0433B22F2998/10B22F2009/043B22F2003/248B22F2301/15B22F2301/255B22F2301/35B22F2301/10C22F1/10C22C33/0285
InventorBELLON, PASCALAVERBACK, ROBERTREN, FUZENG
OwnerTHE BOARD OF TRUSTEES OF THE UNIV OF ILLINOIS