Xtalic Corporation

Apple Inc.

Massachusetts Institute of Technology

Shiyun Ruan

Alan C Lund

Evgeniya Freydina

Christopher Allan Schuh

James A Curran

James A Wright

Joshua Garth Abbott

Robert Daniel Hilty

Lisa J Chan

John Hunter Martin

Witold Paw

Techniques for forming an enclosure comprised of an aluminum alloy are disclosed. In some embodiments, aluminum ions and metal element ions can be dissolved in a non-aqueous ionic liquid in an electrolytic plating bath. A reverse pulsed electric current can facilitate in co-depositing the aluminum ions and the metal element ions onto a metal substrate. The resulting aluminum alloy layer can include nanocrystalline structures, which can impart the alloy layer with increased hardness and increased resistance to scratching, corrosion, and abrasion. In some embodiments, the metal element ion is chromium and the aluminum alloy layer includes a chromium oxide passivation layer formed via a passivation process. Subsequent to the passivation process, the formation of the chromium oxide layer does not impart a change in color to the aluminum alloy layer. In some embodiments, hafnium ions are co-deposited with aluminum ions to form an aluminum hafnium alloy.

Nanostructured aluminum alloys for improved hardness

Techniques for forming an enclosure comprised of aluminum zirconium alloy layer are disclosed. In some embodiments, aluminum ions and zirconium ions can be dissolved in a non-aqueous ionic liquid in an electrolytic plating bath. A reverse pulsed electric current can facilitate in co-depositing the aluminum ions and the zirconium ions onto a metal substrate. The resulting aluminum zirconium alloy layer can include nanocrystalline grain structures, which can impart the alloy layer with increased hardness and increased resistance to scratching, denting, and abrasion. In some embodiments, the aluminum zirconium alloy layer can be anodized to form an aluminum oxide layer. Subsequent to the anodization operation, the oxidized layer is able to retain its substantially neutral color.

Nanostructured aluminum zirconium alloys for improved anodization

An article comprising an electrodeposited aluminum alloy is described herein. The electrodeposited aluminum alloy comprises an average grain size less than approximately 1 micrometer. The electrodeposited aluminum alloy thickness is greater than approximately 40 micrometers. A ductility of the electrodeposited aluminum alloy is greater than approximately 2%.

Articles comprising an electrodeposited aluminum alloys

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&#x2014;Mn alloys have been made with such strength to weight ratios. Additional properties can be controlled, using the shape of the current waveform.

Electrodeposited alloys and methods of making same using power pulses

Metal surface pretreatments using ionic liquids prior to electroplating are disclosed. The surface treatments include forming an activated metal substrate surface by removing any naturally formed metal oxide layers formed on the surfaces of the metal substrates. According to some embodiments, the surface treatments include exposing the metal substrate to a non-aqueous ionic liquid. In some embodiments, an electrical current is applied to the metal substrate to assist removal of the metal oxide layer. The electrical current can be a pulsed anodic current. After activating the surface, a metal layer can be deposited on the activated surface. In some embodiments, the metal layer is electrodeposited in the same ionic liquid used to form the activated surface. The resultant metal coating is resistant to scratching and peeling.

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Arlington, MA, United States of America

Shiyun Ruan