A process for high integrity large thin-walled castings of metals and their alloys using a single downsprue includes the steps of providing at least a sand mold at desired elevated temperatures, delivering a molten metal into the mold, and supplying a predetermined amount of coolant to contact the surfaces of the casting at desired rates, times, and durations to achieve an acceptable level of progressive solidification from the distal end of the casting towards the riser until the casting has reached desired temperatures.

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.

The kit of construction elements includes a plurality of construction elements and a plurality of rod-like binding elements for connecting said construction elements, wherein the construction elements are in the form of square-based rectangles, and wherein on at least one of the faces of each construction element perpendicular to the base thereof at least one groove is formed in parallel to its base, and along at least one edge of each construction element a groove is formed for receiving a binding element, wherein each binding element is formed to fit into a groove along at least a part of its entire length and further provided with securing members formed to engage with complementary securing members of said groove by form-fitting or force-fitting, and wherein the grooves of the construction elements and the binding elements are sized so that during use the construction elements are substantially in contact along their connecting surfaces.

A system for casting an aluminum alloy includes a first chamber for containing a first melt at a first temperature, a second chamber for containing second melt at a second temperature that is lower than the first temperature, a mixing chamber in communication with the first chamber and the second chamber for simultaneously receiving and mixing the first melt from the first chamber with the second melt from the second chamber, and a mold chamber in communication with the mixing chamber and for receiving the mixed melt.

Provided is an aluminum alloy material with high strength and low thermal expansion coefficient even under high temperature environments. An aluminum alloy material according to the present invention has a composition consisting of: Si: 13 mass % to 15 mass %, Cu: 2.0 mass % to 6.0 mass %, Mg: 0.2 mass % to 1.5 mass %, Fe: 0.4 mass % to 0.8 mass %, Ni: 0.2 mass % to 0.8 mass %, P: 0.005 mass % to 0.015 mass %, and the balance being Al and inevitable impurities.

The present disclosure concerns embodiments of aluminum alloy compositions exhibiting superior microstructural stability and strength at high temperatures. The disclosed aluminum alloy compositions comprise particular combinations of components that contribute the ability of the alloys to exhibit improved microstructural stability and hot tearing resistance as compared to conventional alloys. Also disclosed herein are embodiments of methods of making and using the alloys.

A manufacturing method for a metallic housing of an electronic device is provided. The method includes providing a die-casting mold including a male die and a female die; positioning an outer frame in a cavity of the female die, the outer frame including a plurality of latching portions protruding from an inner surface inwardly and a plurality of latching grooves, each latching portion including at least one receiving groove; assembling the male die to the female die; casting pressured molten metal-alloy into the cavity to form an inner structural member embedded in the outer frame, the inner structural member including a plurality of engaging portions respectively embedded in the plurality of receiving grooves, and a plurality of matching portions respectively embedded in the plurality of latching grooves; dissembling the male die from the female die; and removing the outer frame and the inner structural member from the female die.

An exemplary casting assembly for an engine block includes, among other things, an insert and at least one magnet configured to retain the insert in a predefined position within an engine block mold cavity. An exemplary engine block casting method includes, among other things, positioning at least one insert in a mold cavity, retaining the insert in position with at least one magnet, introducing material into the mold cavity to form an engine block, and solidifying the material to secure the insert within the engine block.

A golf strike pad containing silicon carbide, sodium silicate and aluminum-magnesium alloy, wherein: a total volume percentage of the silicon carbide and the sodium silicate is 50% to 68% relative to the golf strike pad; a volume percentage of the aluminum-magnesium alloy is 32% to 50% relative to the golf strike pad; a volume percentage of the silicon carbide is 97% to 99% relative to the total volume of the silicon carbide and the sodium silicate; a volume percentage of the sodium silicate is 1% to 3% relative to the total volume of the silicon carbide and the sodium silicate; and a volume percentage of the aluminum is 92.5% relative to the aluminum-magnesium alloy and the volume percentage of the magnesium is 0.2% to 2% relative to the aluminum-magnesium alloy.

A variable stiffness device, including a core including a low melting point alloy, an encapsulation surrounding the core, the encapsulation made of an elastic material and sealing the core, and a heating device arranged around the encapsulation, configured to heat the core, wherein the elastic material of the encapsulation is subject to a tensile stress in a direction along a longitudinal extension of the thread-like variable stiffness device.