Patents by Inventor Aihua A. Luo
Aihua A. Luo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9593396Abstract: A tin-containing magnesium-aluminum-manganese (Mg—Al—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.Type: GrantFiled: May 16, 2007Date of Patent: March 14, 2017Assignee: GM Global Technology Operations LLCInventors: Aihua A. Luo, Anil K. Sachdev
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Patent number: 9481034Abstract: 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).Type: GrantFiled: December 6, 2013Date of Patent: November 1, 2016Assignee: GM Global Technology Operations LLCInventors: Yiqing Chen, Aihua A. Luo, Anil K. Sachdev
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Patent number: 8992696Abstract: 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.Type: GrantFiled: December 2, 2011Date of Patent: March 31, 2015Assignee: GM Global Technology Operations LLCInventors: Michael J. Walker, Bob R. Powell, Jr., Aihua A. Luo
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Patent number: 8852359Abstract: 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.Type: GrantFiled: December 2, 2011Date of Patent: October 7, 2014Assignee: GM Global Technology Operations LLCInventors: Michael J. Walker, Anil K. Sachdev, Bob R. Powell, Jr., Aihua A. Luo
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Publication number: 20140290894Abstract: 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 comprise aluminum (Al) and the metallic film may comprise zinc (Zn).Type: ApplicationFiled: December 6, 2013Publication date: October 2, 2014Inventors: Yiqing Chen, Aihua A. Luo, Anil K. Sachdev
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Patent number: 8668247Abstract: 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.Type: GrantFiled: April 23, 2012Date of Patent: March 11, 2014Assignee: GM Global Technology Operations LLCInventors: Hamid G. Kia, Aihua A. Luo, John N. Owens, James F. Quinn
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Publication number: 20130278016Abstract: 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.Type: ApplicationFiled: April 23, 2012Publication date: October 24, 2013Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Hamid G. Kia, Aihua A. Luo, John N. Owens, James F. Quinn
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Patent number: 8361251Abstract: 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.Type: GrantFiled: October 20, 2008Date of Patent: January 29, 2013Assignee: GM Global Technology Operations LLCInventors: Aihua A. Luo, Raja K Mishra, Anil K. Sachdev
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Publication number: 20120301734Abstract: 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.Type: ApplicationFiled: December 2, 2011Publication date: November 29, 2012Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Michael J. Walker, Anil K. Sachdev, Bob R. Powell, JR., Aihua A. Luo
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Publication number: 20120301669Abstract: 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.Type: ApplicationFiled: December 2, 2011Publication date: November 29, 2012Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Michael J. Walker, Bob R. Powell, JR., Aihua A. Luo
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Patent number: 8231936Abstract: 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.Type: GrantFiled: December 10, 2008Date of Patent: July 31, 2012Assignee: GM Global Technology Operations LLCInventors: Guangling Song, Aihua A. Luo, Xiaohong Q. Gayden
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Publication number: 20120068497Abstract: Magnesium alloy tube members have the potential to reduce weight in automotive vehicle body structures and other applications but they tend to fragment and fail under compressive stress loads applied end-to-end along the longitudinal axis of the tube. It is found that, when the outside surface of the tube is tightly wrapped with fibers (for example, glass fibers or other suitable fibers) and, optionally, resin bonded to the tube surface, the capacity of the magnesium alloy tube to withstand and absorb compressive loads is greatly increased.Type: ApplicationFiled: September 21, 2010Publication date: March 22, 2012Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Hamid G. Kia, Aihua A. Luo, John N. Owens, James F. Quinn
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Publication number: 20110286880Abstract: One exemplary embodiment includes a cast alloy including Al present in an amount of about 6.5 wt % to about 9.0 wt %; Sn present in an amount of about 1.0 wt % to about 3.0 wt %; Ce present in an amount of about 0 wt % to about 1.0 wt %; and, Mg comprising a balance of the alloy minus an amount of minor and trace elements wherein Mg is present at an amount of greater than about 85 wt %.Type: ApplicationFiled: July 29, 2011Publication date: November 24, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Aihua A. Luo, Anil K. Sachdev
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Patent number: 8052224Abstract: 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.Type: GrantFiled: November 10, 2008Date of Patent: November 8, 2011Assignee: GM Global Technology Operations LLCInventors: Aihua A. Luo, Anil K. Sachdev
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Patent number: 8016957Abstract: 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.Type: GrantFiled: February 3, 2006Date of Patent: September 13, 2011Assignee: GM Global Technology Operations LLCInventors: Xiaoqin Zeng, Yingxin Wang, Wenjiang Ding, Aihua A. Luo
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Patent number: 7967928Abstract: 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.Type: GrantFiled: October 1, 2007Date of Patent: June 28, 2011Assignee: GM Global Technologies Operations LLCInventors: Aihua A Luo, Anil K Sachdev
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Publication number: 20110030855Abstract: A method of improving the corrosion resistance of magnesium alloy castings containing more than about 2 per cent by weight of aluminum is described. The method comprises: first selecting a casting process suitable for developing at least on the surface of the casting a microstructure comprising aluminum-depleted magnesium grains surrounded by an aluminum-rich layer and preferably incorporating at least some of an intermetallic compound based on the composition Mg17Al12; and second, heat treating at least the outer layer of the casting to promote additional intermetallic compound precipitation as required.Type: ApplicationFiled: August 7, 2009Publication date: February 10, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Mridula D. Bharadwaj, Suresh Sundarraj, Shashank Tiwari, Aihua A. Luo, Deepika Sachdeva
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Patent number: 7845388Abstract: 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.Type: GrantFiled: September 28, 2006Date of Patent: December 7, 2010Assignee: GM Global Technology Operations, Inc.Inventors: Aihua A. Luo, Mark W. Verbrugge, Anil K. Sachdev
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Publication number: 20100143746Abstract: 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.Type: ApplicationFiled: December 10, 2008Publication date: June 10, 2010Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Guangling Song, Aihua A. Luo, Xiaohong Q. Gayden
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Publication number: 20100117443Abstract: 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.Type: ApplicationFiled: November 10, 2008Publication date: May 13, 2010Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Aihua A. Luo, Anil K. Sachdev