Abstract: A heat exchanger includes a body defining a flow channel, and a pin extending across the flow channel, the pin including an at least partially non-cylindrical shape. The pin can be a double helix pin including two spiral branches defining a double helix shape. The two branches can include a uniform winding radius. The two branches include a non-uniform winding radius. The non-uniform winding radius can include a base radius and a midpoint radius, wherein the midpoint radius is smaller than the base radius. The two branches can be joined together by one or more cross-members.

Abstract: A heat exchanger can include a monolithically formed body defining at least two channels configured to allow fluid to flow therethrough, at least one of the at least two channels at least partially wrapping around or within at least one other of the at least two channels. In certain embodiments, the at least two channels can include a first channel and a second channel, wherein the first channel is at least partially wound around or within the second channel.

Abstract: A heat exchanger includes a body defining a flow channel, and a pin extending across the flow channel, the pin including an at least partially non-cylindrical shape. The pin can be a double helix pin including two spiral branches defining a double helix shape. The two branches can include a uniform winding radius. The two branches include a non-uniform winding radius. The non-uniform winding radius can include a base radius and a midpoint radius, wherein the midpoint radius is smaller than the base radius. The two branches can be joined together by one or more cross-members.

Abstract: A heat exchanger includes a body defining a flow channel, and a pin extending across the flow channel, the pin including an at least partially non-cylindrical shape. The pin can be a double helix pin including two spiral branches defining a double helix shape. The two branches can include a uniform winding radius. The two branches include a non-uniform winding radius. The non-uniform winding radius can include a base radius and a midpoint radius, wherein the midpoint radius is smaller than the base radius. The two branches can be joined together by one or more cross-members.

Abstract: An airfoil assembly includes an airfoil body extending from a root to a tip defining a longitudinal axis therebetween. The airfoil body includes a leading edge between the root and the tip. A sheath is direct deposited on the airfoil body. The sheath includes at least one metallic material layer conforming to a surface of the airfoil body. In accordance with another aspect, a method for assembling an airfoil assembly includes directly depositing a plurality of material layers on an airfoil body to form a sheath. In accordance with some embodiments, the method includes partially curing the airfoil body.

Abstract: An airfoil assembly includes an airfoil body extending from a root to a tip defining a longitudinal axis therebetween. The airfoil body includes a leading edge between the root and the tip. A sheath is direct deposited on the airfoil body. The sheath includes at least one metallic material layer conforming to a surface of the airfoil body. In accordance with another aspect, a method for assembling an airfoil assembly includes directly depositing a plurality of material layers on an airfoil body to form a sheath. In accordance with some embodiments, the method includes partially curing the airfoil body.

Abstract: A particulate feedstock for an additive manufacturing process includes particles formed from an aluminum base alloy. The alloy includes both aluminum and copper, and the amount of aluminum in the alloy is greater than the amount of copper in the alloy as a percentage of total weight. The alloy also includes at least one other material including at least one of magnesium manganese, titanium, nickel, and boron. The amount of copper in the alloy is greater than the amounts of each of the magnesium, manganese, titanium, nickel, and/or boron included in the alloy to render the particulate amenable to high energy density joining techniques.

Abstract: A heat exchanger includes a body defining a flow channel, and a pin extending across the flow channel, the pin including an at least partially non-cylindrical shape. The pin can be a double helix pin including two spiral branches defining a double helix shape. The two branches can include a uniform winding radius. The two branches include a non-uniform winding radius. The non-uniform winding radius can include a base radius and a midpoint radius, wherein the midpoint radius is smaller than the base radius. The two branches can be joined together by one or more cross-members.

Abstract: A heat exchanger includes a body defining a flow channel, and a pin extending across the flow channel, the pin including an at least partially non-cylindrical shape. The pin can be a double helix pin including two spiral branches defining a double helix shape. The two branches can include a uniform winding radius. The two branches include a non-uniform winding radius. The non-uniform winding radius can include a base radius and a midpoint radius, wherein the midpoint radius is smaller than the base radius. The two branches can be joined together by one or more cross-members.

Abstract: A method includes additively manufacturing an article in an inert environment, removing the article from the inert environment and placing the article in a non-inert environment, allowing at least a portion the article to oxidize in the non-inert environment to form an oxidized layer on a surface of the article, and removing the oxidized layer (e.g., to smooth the surface of the article). The method can further include relieving stress in the article (e.g., via heating the article after additive manufacturing).

Abstract: An inspection method include introducing a mixture of expanding foam and a particulate material into a region of interest of an object, fixing the powder within the region of the interest relative to the object, and acquiring image data of the object and particulate mixture using an x-ray source and an x-ray detector. The particulate has a density that is greater than the density of a material forming the object to provide contrast between the region of interest and the object in an image generated using the image data.

Abstract: A heat exchanger can include a monolithically formed body defining at least two channels configured to allow fluid to flow therethrough, at least one of the at least two channels at least partially wrapping around or within at least one other of the at least two channels. In certain embodiments, the at least two channels can include a first channel and a second channel, wherein the first channel is at least partially wound around or within the second channel.

Abstract: An airfoil assembly includes an airfoil body extending from a root to a tip defining a longitudinal axis therebetween. The airfoil body includes a leading edge between the root and the tip. A sheath is direct deposited on the airfoil body. The sheath includes at least one metallic material layer conforming to a surface of the airfoil body. In accordance with another aspect, a method for assembling an airfoil assembly includes directly depositing a plurality of material layers on an airfoil body to form a sheath. In accordance with some embodiments, the method includes partially curing the airfoil body.

Abstract: A method includes additively manufacturing an article in an inert environment, removing the article from the inert environment and placing the article in a non-inert environment, allowing at least a portion the article to oxidize in the non-inert environment to form an oxidized layer on a surface of the article, and removing the oxidized layer (e.g., to smooth the surface of the article). The method can further include relieving stress in the article (e.g., via heating the article after additive manufacturing).

Abstract: A method for selecting an alloy for additive manufacturing includes melting a first material and a second material together to create a material melt, spinning the material melt to create melt spun ribbons, welding the ribbons together to produce a weld, and determining a weld quality of the weld.

Abstract: An inspection method include introducing a mixture of expanding foam and a particulate material into a region of interest of an object, fixing the powder within the region of the interest relative to the object, and acquiring image data of the object and particulate mixture using an x-ray source and an x-ray detector. The particulate has a density that is greater than the density of a material forming the object to provide contrast between the region of interest and the object in an image generated using the image data.

Abstract: A heat exchanger includes a body defining a flow channel, and a pin extending across the flow channel, the pin including an at least partially non-cylindrical shape. The pin can be a double helix pin including two spiral branches defining a double helix shape. The two branches can include a uniform winding radius. The two branches include a non-uniform winding radius. The non-uniform winding radius can include a base radius and a midpoint radius, wherein the midpoint radius is smaller than the base radius. The two branches can be joined together by one or more cross-members.

Abstract: A cost-effective process for providing a copper-based alloy casting, which has superior wear characteristics, to a cylinder block is described. The process includes heating the copper-based alloy to a molten state for immersing the cylinder block within such, while promoting the entrained gas within the copper-based alloy to migrate in a given direction and terminate in a specified portion of the copper-based alloy to effectively control porosity. In one form, the process further includes cooling the immersed cylinder block in the given direction to effectively reduce microshrinkage of the copper-based alloy.

Abstract: A cost-effective process for providing a copper-based alloy casting, which has superior wear characteristics, to a cylinder block is described. The process includes providing a negative pressure around the cylinder block and a copper-based alloy. The process further includes heating the copper-based alloy to a submolten state for immersing the cylinder block within such, while promoting the entrained gas within the copper-based alloy to migrate in a given direction and terminate in a specified portion of the copper-based alloy to effectively control porosity. The process further includes cooling the immersed cylinder block in the given direction to effectively reduce microshrinkage of the copper-based alloy.

Abstract: A method of making a bearing composed of a bronze preform having aluminum or aluminum alloy cast thereabout. The method includes the step of placing the bronze preform in a mold so as to be supported at one end thereof. The bronze preform is formed of a bronze having lead with a determining melting point and boiling point. The method also includes the step of providing molten aluminum or aluminum alloy to be fed into the mold after the bronze preform has been placed therein. The molten aluminum or aluminum alloy is at a temperature between the melting point and boiling point of lead in the bronze of the bronze preform. The method further includes the step of feeding the molten aluminum or aluminum alloy into the mold under pressure after the bronze preform has been placed therein. The molten aluminum or aluminum alloy contacts the bronze preform and produces a molten lead during partial erosion of the surface thereof.