Abstract: A system for detecting and preventing galvanic corrosion of an anodic metal includes a potential detector configured to monitor an electrical potential within the electrolyte solution, a signal amplifier coupled with the potential detector, and a current delivery circuit coupled with the signal amplifier. The signal amplifier is configured to provide an output proportional to the monitored electrical potential, and the current delivery circuit is configured to provide a current to a cathodic metal that is proportional to the output of the signal amplifier.

Abstract: The surface composition of a metal article may be modified by depositing a coating layer material of a different composition from a consumable tool which is urged against the article surface while being rotated about an axis generally normal to the surface. The frictional heating resulting from rotation of the tool under applied pressure increases the temperature of the article-contacting portion of the tool so that it adheres to and bonds to the magnesium alloy article. In an embodiment the tool material is selected to be more corrosion-resisting than or sacrificial to the substrate metal alloy. In another embodiment the tool material is selected to react with the magnesium surface to form a more corrosion-resistant coating or a sacrificial layer. In another embodiment a holemaking cutting tool may be incorporated in to the consumable tool to enable fabrication of a hole with a surrounding, more corrosion-resistant annular surface.

Abstract: A valve for an anti-lock brake system, wherein the anti-lock brake system is configured for controlling flow of a fluid, includes a housing defining a cavity therein and having a longitudinal axis, a valve seat disposed within the cavity so as to define a first passage for the fluid, and an armature disposed within the cavity so as to at least partially define a second passage for the fluid. The armature is translatable with respect to the valve seat along the longitudinal axis and matable with the valve seat to seal off fluid communication between the first passage and the second passage. The armature defines a surface that is substantially resistant to corrosion from the fluid, and the surface is substantially free from a coating including zinc.

Abstract: An inner body panel for a vehicle, e.g., an inner panel for a trunk lid assembly, is manufactured from a magnesium alloy, and includes an abrasively rounded edge surface along an edge of the panel. The rounded edge surface includes a radius that is equal to one half the thickness of the inner panel. The rounded edge surface allows for a uniform deposition of a corrosion resistant coating along the edge of the panel.

Abstract: A method of manufacturing a closure assembly for a vehicle includes trimming an outer panel to define a first edge and trimming an inner panel to define a second edge, wherein the outer panel is formed from an aluminum alloy material and the inner panel is formed from a magnesium alloy material. The method further includes chemically shaping the second edge to define a substantially rounded edge surface having a radius, positioning the inner panel adjacent the outer panel such that the first edge extends beyond the substantially rounded edge surface, and bending the first edge of the outer panel around the substantially rounded edge surface of the inner panel to form a hem connection that secures the inner panel relative to the outer panel. A closure assembly is also disclosed.

Abstract: A method of controlling corrosion at an interface formed between at least two metal components includes applying a blend of magnesium particles and one of an adhesive or a sealant to the interface. The magnesium particles have a diameter sufficient to span a distance between the metal components. The method further includes exposing the metal components to a substantially corrosive environment, where the corrosive environment at least partially dissolves the magnesium particles. At least partial dissolution of the magnesium particles i) cathodically protects the metal components at the interface, ii) alkalizes the corrosive environment, and iii) generates hydrogen bubbles that substantially block a crevice formed at the interface.

Abstract: A sealed hemmed closure assembly includes an inner panel having a first face and a second face, and an outer panel having a panel portion and a hemming portion. The second face of the inner panel substantially opposes the first face, and the hemming portion of the outer panel is disposed proximate an edge of the outer panel. The panel portion of the outer face is configured to abut the first face of the inner panel, and the hemming portion is configured to abut the second face of the inner panel. An adhesive material is disposed between the panel portion of the outer panel and the first face of the inner panel, and a sealant material is disposed between the hemming portion of the outer panel and the second face of the inner panel.

Abstract: A system for detecting and preventing galvanic corrosion of an anodic metal includes a potential detector configured to monitor an electrical potential within the electrolyte solution, a signal amplifier coupled with the potential detector, and a current delivery circuit coupled with the signal amplifier. The signal amplifier is configured to provide an output proportional to the monitored electrical potential, and the current delivery circuit is configured to provide a current to a cathodic metal that is proportional to the output of the signal amplifier.

Abstract: Methods of reducing corrosion between magnesium and another metal are disclosed herein. In one method, a corrosion protection material is cold sprayed at an interface formed between the magnesium and the other metal, the corrosion protection material including magnesium. In another method, a cladding layer is applied to heat affected areas of the magnesium and/or the other metal, at a welded joint, or combinations thereof.

Abstract: A method is disclosed for improving the corrosion behavior of cast magnesium alloy articles in which the magnesium alloy comprises an average composition of more than about 5 per cent by weight of aluminum. A microstructure with regions of varying aluminum content is developed during solidification. The microstructure comprises magnesium-rich grains generally surrounded by an aluminum-enriched phase on the boundaries between adjacent grains The magnesium-rich grain interiors are then selectively chemically or electrochemically attacked to leave a more corrosion resistant aluminum-enriched surface on the articles. The corrosion resistance of the articles may be further enhanced by one or more of anodizing, aluminizing or painting the corrosion-resistant aluminum-enriched surface.

Abstract: Some articles such as automobile components that have been constructed from steel and/or aluminum alloy parts are now being fitted with magnesium parts whose surfaces may need to be protected against corrosion. To do this an e-coating pre-film may be formed on the part's magnesium surfaces by exposing it to a conventional e-coating emulsion. And there is no need to supply a current or potential to the part or component. Magnesium's high reactivity with acidic or neutral aqueous mediums is itself a sufficient driving force to facilitate the deposition of an e-coating pre-film. At the same time any steel or aluminum alloy parts will remain unaffected. The article with a protective e-coating pre-film formed solely on its magnesium surfaces may now be advanced through a paint-line that includes conventional processes aimed at treating the component's steel and aluminum alloy parts. The process may be practiced where the magnesium surface comprises a magnesium-containing conversion or anodized coating.

Abstract: A method of coating a magnesium-based substrate includes applying a first potential of electric current to the substrate and, after applying, immersing the substrate in an electrocoat coating composition. After immersing, a second potential of electric current is applied between the substrate and a counter electrode to deposit the electrocoat coating composition onto the substrate. The second potential is greater than the first potential. The method also includes curing the electrocoat coating composition to form a cured film and thereby coat the substrate. An electrocoat coating system includes the magnesium-based substrate, and the cured film disposed on the substrate and formed from the electrocoat coating composition. The substrate exhibits a negative charge from an applied first potential of electric current of ? approximately 40 V prior to contact with the electrocoat coating composition.

Abstract: A method of forming a coated article is disclosed. The method involves heating a magnesium alloy component, positioning the component in a mold such that a gap exists between component outer surfaces and mold inner surfaces, and heating a magnesium-containing alloy material above its melting temperature, which is lower than that of the component. The material is formed from magnesium alloyed with i) the component element, but at a higher concentration, ii) at least one element that is different than the component element, or iii) the component element and at least one other element. The method further includes introducing the material into the gap, thereby covering at least the outer surfaces of the component, and cooling the material to form a substantially evenly distributed solidified coating on the outer surfaces of the component. The coating has a higher wear and/or corrosion resistance than that of the magnesium alloy component.

Abstract: Surfaces of magnesium-base alloy workpieces may be mechanically worked and deformed to increase their resistance to corrosion, especially corrosion occurring in the presence of water or water and salt or other corrosive media. Workpiece surfaces that are to be thus protected are engaged in squeezing, sliding, and frictional contact with a suitable burnishing or other working tool that traverses the surface to compress and deform it and to refine the metallurgical grain structure. For example, the grain size is reduced in a surface layer that may extend to a depth of up to a few millimeters. And grain orientation is altered within that depth. The tool is not employed to intentionally remove material from the surface of the workpiece. The initial dimensioning of the workpiece may take into consideration the alteration of surfaces by the mechanical working process.

Abstract: A method of preparing a magnesium alloy substrate for an electroless electro-deposition surface treatment includes cleaning the magnesium alloy substrate in a wet solution, whereby a magnesium hydroxide layer is formed on an outer surface of the magnesium alloy substrate, and heating the magnesium alloy substrate to a temperature sufficient to convert the magnesium hydroxide layer to a magnesium oxide layer.

Abstract: Elemental magnesium coatings and methods of applying them to surfaces of magnesium-based alloy articles of manufacture are described. Such coatings may be chosen to be anodic to magnesium and may thus, when applied to magnesium articles, be sacrificial and afford corrosion protection to the articles. The utility of such coatings may be enhanced by supplementing them with a barrier coating such as a passive magnesium-containing alloy, a conversion or anodic coating or paint overlying the sacrificial coating. Methods of applying sacrificial coatings to a magnesium-based alloy article are described and include physical vapor deposition on the article, electrodeposition on the article and dipping the article in molten alloy.

Abstract: An electrode assembly for use with an electrodeposition process. According to an exemplary embodiment, the electrode assembly includes an electrode for exchanging electrical current with a solution, a passageway for removing gas that becomes trapped between a workpiece and the solution, and a sleeve for electrically isolating the electrode from the workpiece.

Abstract: A method of coating a magnesium-based substrate includes applying a first potential of electric current to the substrate and, after applying, immersing the substrate in an electrocoat coating composition. After immersing, a second potential of electric current is applied between the substrate and a counter electrode to deposit the electrocoat coating composition onto the substrate. The second potential is greater than the first potential. The method also includes curing the electrocoat coating composition to form a cured film and thereby coat the substrate. An electrocoat coating system includes the magnesium-based substrate, and the cured film disposed on the substrate and formed from the electrocoat coating composition. The substrate exhibits a negative charge from an applied first potential of electric current of ? approximately 40 V prior to contact with the electrocoat coating composition.

Abstract: An engine includes a cylinder head at least partially defining a valve seat pocket. A valve seat is located proximate to the cylinder head to at lest partially define the valve seat pocket. A pocket filler is located between the valve seat and the pocket insert such that the pocket filler occupies a substantial portion of the valve seat pocket. A pocket insert is attached to the cylinder head proximate to the valve seat pocket, such that the pocket insert lines at least a portion of the valve seat pocket.

Abstract: A major engine casting, such as an engine block or a cylinder head, fabricated of either magnesium or aluminum alloy, has a cast-in-place metal tube or form embedded within it. The tube or form enables circulation of liquid while substantially physically isolating the casting alloy from the circulating liquid and thereby restricting or eliminating corrosive interaction between them.