Methods and apparatus for a composite bicycle front sprocket are disclosed herein. One embodiment discloses a composite bicycle front sprocket assembly having an outer assembly of a first material. The bicycle front sprocket assembly also has a center assembly of a second material. The center assembly is disposed at least partially within the outer assembly. The center assembly is irremovably coupled with the outer assembly. The center assembly is irremovably coupled with the outer assembly without an external fastening device to irremovably couple the center assembly with the outer assembly.

A castable, moldable, and/or extrudable structure using a metallic primary alloy. One or more additives are added to the metallic primary alloy so that in situ galvanically-active reinforcement particles are formed in the melt or on cooling from the melt. The composite contains an optimal composition and morphology to achieve a specific galvanic corrosion rate in the entire composite. The in situ formed galvanically-active particles can be used to enhance mechanical properties of the composite, such as ductility and/or tensile strength. The final casting can also he enhanced by heat treatment, as well as deformation processing such as extrusion, forging, or rolling, to further improve the strength of the final composite over the as-cast material.

An aluminum alloy for casting, made of an Al—Si—Cu—Mg alloy which consists of specific amounts of Si, Cu, and Mg, in addition to specifically desired amounts of titanium, phosphorus, boron, and optional additional chemical elements sodium and strontium, with the balance of the aluminum alloy comprising aluminum and any impurities. When a content of phosphorus is defined as X mass %, the content of phosphorus, a content of Y mass % of sodium, and a content of Z mass % of strontium satisfy the following relationships: 0.45Y+0.24Z+0.003≤X≤0.45Y+0.24Z+0.01; 0≤Y≤0.01; and 0≤Z≤0.03. The aluminum alloy ensures surface smoothness of a cast article by specifying the phosphorus content. This minimizes a surface segregation layer, even in production of a cast article using a molten metal containing a eutectic structure modifier such as sodium.

Provided is a cylinder liner having a first portion with a first thermal conductivity and a second portion with a second thermal conductivity. The first portion having the first thermal conductivity can include as-cast projections or a coating of a material, as desired. The first thermal conductivity can be greater than the second thermal conductivity. In this manner, the cylinder liner can exhibit a thermal conductivity gradient.

A method of over-molding a hybrid sub-assembly onto a base structure includes providing a mold for an over-molding process. The mold may comprise a lower mold tool, an upper mold tool, and a tube locator positioned on one of the upper mold tool or lower mold tool. A base structure formed of a first material is located into the tube locator. A mandrel tool is inserted into an opening in the base structure. The upper and lower mold tools are closed and clamped shut. A second material, such as a lighter weight or lower density material is heated to at least a semi-solid or slurry state. The semi-solid or slurry is injected into the mold to form a molded sub-assembly that is mechanically bonded to the base structure.

A CAE analysis die model is produced such that a cavity of a die for obtaining a cast product is divided into multiple elements. Fluidity analysis and solidification analysis are performed under a predetermined casting condition by means of the die model to calculate, for each element, a factor regarding growth of a solidification structure, a factor regarding purity of molten metal, and a factor regarding a hole defect. Mechanical characteristics of each portion of the cast product are obtained by a regression expression obtained by multiple regression analysis using mechanical characteristics of the cast product as an objective variable and using each factor as an explanatory variable.

A method for manufacturing a high-quality aluminum casting includes preparing an aluminum alloy raw material including Si in an amount of 9-12 wt %, melting the raw material to prepare a molten metal, adding a refiner containing Ti, B, and Sr to the molten metal, injecting the molten metal into a casting apparatus to maintain the temperature of the molten metal added with the refiner at 585-610° C., and operating the casting apparatus to cast the injected molten metal into a product having a predetermined shape.

A method and machine for continuous casting of a strip of a plurality of serially connected battery grids. The machine may have a rotatable annular mold ring with a cavity at least in part having a plurality of grid molds, and a movable belt overlying at least the axial extent and a portion of the circumferential extent of the mold cavity in at least the area where liquid lead may be supplied to the mold cavity. To supply liquid lead to the mold cavity the mold ring may have a runner system communicating with the mold grids and opening to an end of the mold ring.

A process for the manufacture of metal products includes the steps of providing a mold including a first portion made of an aggregate and a binder, delivering a molten metal into the mold, removing a first portion of the mold with a fluid and solidifying at least one targeted portion of the molten metal which will form the metal product with the fluid. A flow of fluid to the mold is stopped for a period of time. Subsequently, a remaining portion of the molten metal is solidified to form the metal product. The at least one targeted portion of the metal product has better mechanical properties than does a remaining portion of the metal product. A unitary, one-piece aluminum alloy component with differing mechanical properties is also disclosed.

Described herein are novel aluminum containing alloys. The alloys are highly formable and can be used for producing highly shaped aluminum products, including bottles and cans.