Gm Global Technolgoy Operations, Inc.

Aihua A Luo

Anil Kumar Sachdev

Bob Ross Powell

Michael J Walker

Mark William Verbrugge

Hamid Ghavami Kia

John Neal Owens

Xiaohong Gayden

Guangling Song

Raja K Mishra

Wenjiang Ding

Basant L Tiwari

Vadim Rezhets

Xiaoqin Zeng

James F Quinn

Yingxin Wang

Yiqing Chen

A tin-containing magnesium-aluminum-manganese (Mg&#x2014;Al&#x2014;Mn) based alloy that provides a desired combination of strength and ductility so as to be particularly suited for structural applications. The alloy includes magnesium, aluminum, and manganese in combination and about 0.5% to about 3.5% tin. The tin addition improves strength without substantial loss of ductility.

High strength/ductility magnesium-based alloys for structural applications

Methods of forming bi-metallic castings are provided. In one method, a metal preform of a desired base shape is provided defining a substrate surface. A natural oxide layer is removed from the substrate surface, yielding a cleaned metal preform. The method includes forming a thin metallic film on at least a portion of the substrate surface of the cleaned metal preform, and metallurgically bonding the portion of the metal preform having the metallic film with an overcast metal to form a bi-metallic casting. The metallic film promotes a metallurgical bond between the metal preform and the overcast metal. In one aspect, the metal preform may include aluminum (Al) and the metallic film may include zinc (Zn).

Surface treatment for improved bonding in bi-metallic casting

A method of bonding a metal to a substrate involves forming a plurality of nano-features in a surface of the substrate, where each nano-feature is chosen from a nano-pore and/or a nano-crevice. In a molten state, the metal is over-cast onto the substrate surface, and penetrates the nano-features. Upon cooling, the metal is solidified inside the nano-features, where the solidification of the metal forms a mechanical interlock between the over-cast metal and the substrate.

Method of bonding a metal to a substrate

A method of bonding a metal to a substrate involves forming an oxide layer on a surface of the substrate, and in a molten state, over-casting the metal on the substrate surface. The over-casting drives a reaction at an interface between the over-cast metal and the oxide layer to form another oxide. The other oxide binds the metal to the substrate surface upon solidification of the over-cast metal.

A segmented tube formed of a magnesium-based alloy and wrapped or jacketed with a reinforcement to apply a restraining force on the external surface of the tube for resisting fragmentation of the tube by the compressive force applied to the end of the tube serves as a structural member for receiving a compressive stress applied to an end of the tube and acting along the axis of the tube toward the opposing end of the tube. The magnesium alloy tube is comparatively light, and the segmented and wrapped or jacketed tube has an increased capacity to absorb compressive forces. The tubes are useful as components of automotive vehicles.

Magnesium-composite structures with enhanced design

A magnesium alloy comprising up to about six weight percent zinc and up to about one weight percent cerium may be hot worked to produce an intermediate or final alloy workpiece that exhibits enhanced ductility and strength at room temperature. The addition of zinc and a small amount of cerium may affect the magnesium alloy by increasing strength and ductility, and improving the work hardening behavior.

High ductility/strength magnesium alloys

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.

Methods of reducing corrosion between magnesium and another metal

One embodiment includes a wheel including a first portion including magnesium, the first portion including at least a rim; a second portion including aluminum; and an interface where the first portion and the second portion contact each other.

Lightweight aluminum wheel with magnesium rim

The grain size of magnesium alloys is effectively refined and made smaller by the addition of a small amount of titanium. The effect of the reduction of grain size is often an improvement in the strength and processability of a cast magnesium alloy. Often less than about 0.1% by weight of titanium need be used. It may be preferred to incorporate the titanium with another alloying constituent (such as aluminum) for addition to a melt of a magnesium base alloy.

Magnesium grain-refining using titanium

Methods of extruding magnesium-based casting alloys are provided. The magnesium alloys have relatively high strength and castibility, as well as an improved ductility and extrudability for wrought alloy applications. The magnesium-based wrought alloy comprises aluminum (Al) of between about 2.5 to about 3.5 wt. %, manganese (Mn) of less than about 0.6 wt. %, zinc (Zn) of less than about 0.22 wt. %, other impurities of less than about 0.1 wt. %, and a balance of magnesium (Mg). The disclosure provides various methods of forming extruded structural components, including automotive components, and methods of forming such wrought alloys.

Methods of extruding magnesium alloys

Magnesium or magnesium alloy components having galvanic corrosion protection isolators secured in place by metallurgical bonding during casting of the magnesium or magnesium alloy component. The isolators are formed of materials that are characterized by an absolute potential difference that is between that of magnesium and a contacting metallic component.

Galvanic corrosion protection for magnesium components using cast-in-place isolators

An instrument panel beam includes an elongated main member having a bent tubular configuration, and a plurality of structural supports connected to the member. The beam is formed of a lightweight material, such as a magnesium or aluminum alloy. The beam is preferably constructed utilizing a die-cast process, wherein at least a portion of the member is overmolded by each support so as to cooperatively form a soldered region therebetween.

Lightweight hybrid tubular/casting instrument panel beam

A method for bending magnesium alloy tubes. The method includes heating the tube at moderate temperature in the range of about 100&#xb0; C. to 200&#xb0; C., and bending the tube to a bend angle or forming the tube to a desired shape.

Moderate temperature bending of magnesium alloy tubes

The present invention provides a process for forming aluminum alloy hydroformed structures for automotive vehicles at low cost. The process continuously casts molten aluminum alloy into aluminum alloy strip material preferably followed by continuously warm rolling the strip material into aluminum alloy sheet material. The sheet material is formed into one or more aluminum alloy tubes and the tubes are hydroformed into the desired automotive vehicle structure.

Process for forming aluminum hydroforms

A family of die castable, creep-resistant magnesium alloys has been developed for high-temperature structural applications such as automotive engines and transmission cases. These alloys contain between 3% and 6% aluminum, 1.7% and 3.3% calcium, and up to 0.2% strontium. They have demonstrated 25% greater tensile and compressive creep resistance than AE42, a commercial aluminum, rare earth containing magnesium alloy, and corrosion resistance as good as AZ91D. These alloys are estimated to cost less than AZ91D and have good castability in metal molds as used in permanent mold casting and die casting.

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Troy, MI, United States of America

Aihua A Luo