Electrodeposited alloys and methods of making same using power pulses

Patent metadata

Field	Value
Publication number	US-10030312-B2
Application number	US-57906209-A
Country	US
Kind code	B2
Filing date	Oct 14, 2009
Priority date	Oct 14, 2009
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

Power pulsing, such as current pulsing, is used to control the structures of metals and alloys electrodeposited in non-aqueous electrolytes. Using waveforms containing different types of pulses: cathodic, off-time and anodic, internal microstructure, such as grain size, phase composition, phase domain size, phase arrangement or distribution and surface morphologies of the as-deposited alloys can be tailored. Additionally, these alloys exhibit superior macroscopic mechanical properties, such as strength, hardness, ductility and density. Waveform shape methods can produce aluminum alloys that are comparably hard (about 5 GPa and as ductile (about 13% elongation at fracture) as steel yet nearly as light as aluminum; or, stated differently, harder than aluminum alloys, yet lighter than steel, at a similar ductility. Al—Mn alloys have been made with such strength to weight ratios. Additional properties can be controlled, using the shape of the current waveform.

First claim

What is claimed is:

1. A method for depositing an alloy comprising aluminum and manganese, the method comprising the steps of:
a. providing a non-aqueous electrolyte comprising dissolved species of aluminum and manganese the non-aqueous electrolyte comprising an ionic liquid;
b. providing a first electrode and a second electrode in the electrolyte, coupled to a power supply; and
c. driving the power supply to deliver electrical power to the electrodes, the electrical power having waveforms comprising a plurality of modules, at least one module comprising at least two pulses, the first pulse having a cathodic power with an amplitude of i 1 that is positive, applied over a duration t 1 , and the second pulse having an amplitude of value i 2 that is applied over a duration t 2 , further where both t 1 and t 2 are greater than about 0.1 milliseconds and less than about 1 second in duration, and wherein the ratio i 2 /i 1 is greater than about −0.625 and less than zero (0);
whereby an alloy deposit comprising aluminum and manganese arises upon the second electrode, the alloy deposit having a ductility of between about 5% and about 100%.

2. The method of claim 1 , the deposit comprising at least about 50% Al by weight.

3. The method of claim 1 , wherein the step of driving the power supply further comprises driving the power supply to supply electrical power such that one of the plurality of modules comprises off-time and an additional cathodic pulse.

4. The method of claim 1 , wherein the step of driving the power supply further comprises driving the power supply to supply electrical power such that one of the plurality of modules comprises at least two cathodic pulses of different magnitudes.

5. The method of claim 1 , the step of driving comprising driving the power supply with a non-constant electrical power having a repeating waveform with modules having a duration of between about 0.2 ms and about 2000 ms.

6. The method of claim 1 , the deposit having a characteristic microstructural length scale of less than about 100 nm.

7. The method of claim 1 , where the step of providing an electrolyte further comprises providing a non-aqueous electrolyte comprising dissolved species of at least one other element that is not aluminum and manganese.

8. The method of claim 7 , wherein there exists a correlation between the electrolyte composition with respect to the at least one other element and a property of a formed alloy, which correlation is continuous over a range of practical use of the deposit, further comprising the steps of:
a. based on the correlation, determining the composition with respect to the at least one other element that corresponds to a target degree for the property; and
b. the step of providing a non-aqueous electrolyte comprises providing an electrolyte with the corresponding composition.

9. The method of claim 8 , the property of the formed alloy comprising average characteristic size of surface features.

10. The method of claim 8 , the property of the formed alloy comprising surface morphology.

11. The method of claim 10 , the property comprising surface morphology, the target degree comprising surface morphology ranging from highly facetted structures, to less angular features, to a smooth surface, and to rounded nodules.

12. The method of claim 8 , the property of the formed alloy comprising average characteristic microstructural length scale.

13. The method of claim 12 , the target value for average characteristic microstructural length scale being between approximately 15 nm and approximately 2500 nm.

14. The method of claim 1 , wherein there exists a correlation between the value of at least one of: the pulse amplitudes, the amplitude ratios, and duration of the pulses; and a degree of a property of a formed alloy, which correlation is continuous over a range of practical use of the deposit, further comprising the steps of:
a. based on the correlation, determining the value of at least one of amplitude, amplitude ratio or duration that corresponds to a target degree for the property; and
b. the step of driving the power supply comprising driving the power supply to supply electrical power with modules having pulses, having the determined value of the at least one of the amplitude, amplitude ratio or duration that corresponds to a target degree for the property, to achieve the deposit at the second electrode having the target degree for the property.

15. The method of claim 14 , the step of determining the value of at least one of the amplitude, amplitude ratio and duration comprising determining a second value of at least one of the amplitude, amplitude ratio and duration that correspond to a second target degree for the property, and the step of driving the power supply comprising alternately driving the power supply to supply electrical power with modules having pulses, having the value of the first at least one amplitude, amplitude ratio and duration that corresponds to a first target degree for the property, and then driving the power supply to supply electrical power with modules having pulses, having the value of the second at least one amplitude, amplitude ratio and duration that corresponds to the second target degree for the property, whereby an article is produced having a structure with regions that exhibit the property with the first target degree, and with regions that exhibit the property with the second target degree.

16. The method of claim 1 , comprising:
the step of driving the power supply comprising driving the power supply to deliver electrical power to the electrodes for a first period of time, thereby producing at the cathode a first portion of the deposit with at least one property chosen from the group consisting of hardness, ductility, composition, characteristic microstructural length scale, and phase arrangement having a first degree;
and driving the power supply to deliver electrical power to the electrodes for a second period of time, having waveforms comprising modules comprising at least two pulses, the first pulse having a cathodic power with an amplitude of i 1* that is positive, applied over a duration t 1* , and the second pulse having a power of value i 2* that is applied over a duration t 2* , further where both t 1* and t 2* are greater than about 0.1 milliseconds and less than about 1 second in duration, and further where the ratio i 2* /i 1* is less than about 0.99 and greater than about −10, and where at least one of the following inequalities is true: i 1 ≠i 1* ; i 2 ≠i 2* ; t 1 ≠t 1* ; t 2 ≠t 2* ; producing at the cathode a second portion of the deposit with the at least one property having a second, different degree.

17. The method of claim 1 , the electrical power comprising electrical current.

18. The method of claim 1 , the non-aqueous electrolyte comprising 1-ethyl-3-methylimidazolium chloride.

19. The method of claim 1 , wherein the ratio i 2 /i 1 is greater than about −0.5.

Assignees

• Ruan Shiyun
• Schuh Christopher A
• Massachusetts Inst Technology

Inventors

• Ruan Shiyun
• Schuh Christopher A

Classifications

• C25D3/66 Primary

  from melts · CPC title

• C25C3/18

  Electrolytes · CPC title

• C25D3/665 Primary

  from ionic liquids · CPC title

• C25C3/06

  of aluminium · CPC title

• C25D5/10

  Electroplating with more than one layer of the same or of different metals (for bearings C25D7/10) · CPC title