Metallic Structures with Variable Properties

Abstract

Variable property deposit, at least partially of fine-grained metallic material, optionally containing solid particulates dispersed therein, is disclosed. The electrodeposition conditions in a single plating cell are suitably adjusted to once or repeatedly vary at least one property in the deposit direction. In one embodiment denoted multidimension grading, property variation along the length and / or width of the deposit is also provided. Variable property metallic material deposits containing at least in part a fine-grained microstructure and variable property in the deposit direction and optionally multidimensionally, provide superior overall mechanical properties compared to monolithic fine-grained (average grain size: >20 micron) or entirely amorphous metallic material deposits.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This is a continuation-in-part of U.S. patent application Ser. No. 12 / 003,224, filed Dec. 20, 2007.TECHNICAL FIELD[0002]The invention is directed to the direct current (DC) or pulsed electrodeposition of a metallic material to provide a variable property product containing, at least in part, a fine-grained metallic material with an average grain-size between 2 and 10,000 nm.BACKGROUND OF THE INVENTION[0003]Modern lightweight and durable articles require a variety of physical properties which are oftentimes not achievable with a monolithic material synthesis approach. Materials with variable properties, that is variation in a property among levels or layers, throughout the depth of the article, are described in prior art. These include parts with graded properties (such that the distinct levels or layers exhibit differing porosities, chemical compositions, grain sizes, filler amounts and / or hardness values), that is having in different lev...

AI Technical Summary

Benefits of technology

"The invention is about a method for producing a thick metallic deposit with a variable microstructure that can have several properties, such as grain size, crystallographic orientation, and hardness, in different parts of the deposit. The method involves adjusting electrodeposition parameters, such as current density, pulse on time, and duty cycle, to create the desired microstructure. The resulting deposit can be used as a coating or a layer in a composite material, improving durability and reducing failure. The method can be performed in a single tank, reducing costs and the risk of contamination. The invention also provides uninterrupted formation of variable property structures using a single plating tank by adjusting electrodeposition parameters. The fine-grained metallic microstructure is contained in a single layer or multiple layers that in total represent at least 5% of the cross-sectional thickness of the deposit."

Problems solved by technology

This method is limited in its practical utility insofar as deleterious impurity contamination is frequently unavoidable, component shape flexibility is limited, the process is energy intensive, and is not readily scalable.

This method has the disadvantages that it is not applicable to pure metals, i.e., is only applicable to alloys, and that it is dependent for grading on changing Polarity Ratio, a parameter that is not directly supplied to the system.

The employment of reverse (anodic) pulses requires expensive power supplies and results in a significantly reduced plating efficiency as metal dissolution occurs during the reverse pulses.

Images