Provided is a surface hardening method for surface hardening a sulfuric acid-anodized aluminum alloy oxide layer, which includes: pre-treatment in which various foreign substances, including an oxide film, attached to a surface of an aluminum alloy are removed; sealing treatment in which the aluminum alloy having been subjected to the pre-treatment is immersed in a sealing solution, whereby fine pores formed in a film are sealed; and heat treatment in which the aluminum alloy having been subjected to the sealing treatment is charged to, and thermally treated in, a heat treatment furnace and then naturally cooled. By lowering the withstand voltage of an aluminum alloy oxide layer and increasing the hardness by subjecting the same to sealing treatment and subsequent post-heat treatment, the present invention has the effect of providing an environmentally-friendly and crack-free lightweight material that can replace steel products.

An electronic device according to various embodiments of the disclosure may include: a display; and a housing including the display, at least a portion of the housing including: an aluminum alloy machined to have a designated shape; a first film layer formed on the aluminum alloy; and a second film layer formed between the aluminum alloy and the first film layer, wherein the first film layer may be formed by a first anodizing process using a first voltage on the aluminum alloy, and the second film layer may be formed by a second anodizing process using a second voltage on the aluminum alloy after the first anodizing process.

Development of an alternative process to conventional toxic chromic acid anodization (CAA) with equivalent corrosion resistance is a challenging task. The present invention provides a chromate free process for the manufacture of corrosion resistant sealed anodized coating for long term corrosion resistance of aerospace grade aluminum alloy. This method includes the steps of cleaning, chemical etching, anodizing in Tartaric-Sulphuric acid electrolyte followed by dipping the specimen in the sealing bath containing at least two water soluble either Mn and Mo or Mn and V oxyanions as corrosion inhibitors and a sufficient amount of alkali metal ion based nitrates at a temperature range between 60 and 80° C. for about 20 to 40 minutes at a pH range of 7 to 9. The sealed anodic coatings developed from this invention showed improved corrosion resistance in neutral 5% NaCl fog environment for greater than 2000 h of exposure. The sealed anodic coatings developed by this invention also showed self-healing protection in NaCl environment.

The present invention provides a self-healing anti-icing ACSR with composite microporous structure, which is formed lower layer pores with a small diameter (durable storage remediator) and upper layer pores with a large diameter (increase a proportion of air cushion to improve anti-icing performance) by growing a uniform porous aluminum membrane on the surface of an aluminum base body. By optimizing the diameter and thickness of the lower layer pores and upper layer pores, and under the action of air pressure, capillary force and surface energy, a low surface energy remediator is immersed in pores, so an anti-icing ACSR with durable excellent anti-icing self-healing performance is prepared. The invention improves the anti-icing performance of the ACSR in practical applications and the self-healing of the anti-icing performance after being damaged, thereby extending the anti-icing life of the ACSR and improving the durable anti-icing performance thereof.

The present disclosure is drawn to covers for electronic devices, methods of making the covers, and electronic devices. In one example, described herein is a cover for an electronic device comprising: a substrate comprising a metal; insert molded plastic on at least one surface of the substrate; a passivation layer or a micro-arc oxidation layer applied on at least one surface of the substrate; a coating composition on the passivation layer or the micro-arc oxidation layer; an outmoid decoration layer on the mating composition; a chamfered edge on the substrate, wherein the chamfered edge cuts through the outmoid decoration layer, the coating composition, the passivation layer or the micro-arc oxidation layer, and partially through the substrate; and wherein the chamfered edge comprises; a transparent passivation layer, then an optional sealing layer, and then a transparent or color electrophoretic deposition coating layer.

A method of manufacturing an extruded material of carbon nanotube reinforced aluminum matrix composite having improved corrosion resistance, and the extruded material manufactured thereby are proposed. The method may include manufacturing an extruded material comprising an aluminum-carbon nanotube composite material and forming a hard oxide film on the surface of the extruded material by anodizing the extruded material in a mixed solution of sulfuric acid and oxalic acid. The method can form a hard oxide film with excellent corrosion resistance, abrasion resistance, and insulation properties on the surface of a composite material (an extruded material of carbon nanotube reinforced aluminum matrix composite material), which is known to be difficult to conduct hard anodizing due to the difference in corrosion characteristics between materials and, accordingly, the usability of the composite material can be significantly improved.

In a method, an aluminum body is chemically treated with at least one of an alkaline solution and an acid solution. Anode-oxidization is performed on the chemically treated aluminum body to form an aluminum oxide layer. The aluminum oxide layer is treated with hot water at a temperature more than 75° C. or steam. The aluminum oxide layer after being treated with hot water or steam includes plural columnar grains, and an average width of the columnar grains is in a range from 10 nm to 100 nm.

A medical scope device such as an endoscope is produced using a cast aluminum process including a molten casting aluminum alloy including a maximum of 0.2 - 0.3% Si and at least 5% Zn. The process includes providing an investment casting mold, casting the aluminum alloy in the mold to create a component and removing the mold from the component, post-machining the component to meet a desired specification, and after post-machining the component, performing surface finishing, such as centrifugal barrel finishing (CBF) sufficient to remove impurities on casting surfaces by 2 - 3 mils, then coating the component with a micro-crystalline aluminum anodic coating of at least 0.5 mil thickness. A medical scope and product-by-process is also provided employing such techniques.

Various components of an electronic device housing and methods for their assembly are disclosed. The housing can be formed by assembling and connecting two or more different sections together. The sections of the housing may be coupled together using one or more coupling members. The coupling members may be formed using a two-shot molding process in which the first shot forms a structural portion of the coupling members, and the second shot forms cosmetic portions of the coupling members.

Anodic oxide coatings that provide corrosion resistance to parts having protruding features, such as edges, corners and convex-shaped features, are described. According to some embodiments, the anodic oxide coatings include an inner porous layer and an outer porous layer. The inner layer is adjacent to an underlying metal substrate and is formed under compressive stress anodizing conditions that allow the inner porous layer to be formed generally crack-free. In this way, the inner porous layer acts as a barrier that prevents water or other corrosion-inducing agents from reaching the underlying metal substrate. The outer porous layer can be thicker and harder than the inner porous layer, thereby increasing the overall hardness of the anodic oxide coating.