CITIC Dicastal Co., Ltd.

The present invention discloses a low-pressure mold and production process for aluminum alloy integrated brake calipers, relating to the technical field of casting. The mold comprises a bottom plate, a right mold core and a left mold core are provided on the bottom plate, and the right mold core and the left mold core have the same internal structure and are each provided with a sprue assembly. The low-pressure casting process has higher production efficiency and yield than gravity casting. Castings produced by low-pressure casting have higher structural compactness and more excellent mechanical properties than those produced by gravity casting.

The application discloses a preparation method for an aluminum alloy cavity casting filled with special-shaped foamed aluminum. The preparation method includes: preparing special-shaped foamed aluminum in a first mold by adopting a powder metallurgy foaming method; fixing the special-shaped foamed aluminum coated with the soldering flux in a second mold after the special-shaped foamed aluminum is coated with soldering flux; and casting by using molten aluminum alloy. According to the preparation method for the aluminum alloy cavity casting filled with the special-shaped foamed aluminum, the overall strength of the casting can be improved while the wall thickness of the casting is reduced to meet the requirement that the overall quality of the casting is not increased.

An aluminum alloy material smelting device comprises a furnace and a packing device with a packing basket, a stirring shaft connected with the packing basket and a stirring head connected with the bottom of the packing basket. The stirring head comprises a plurality of stirring blades with one end connected with the bottom of the packing basket and another end connected with each other on the central axis of the packing basket. The side wall of the packing basket is provided with a liquid passage hole to exchange liquid with the solution outside the packing basket. By rotating the stirring head, a solution vortex accelerating the diffusion of added elements can be formed only under the stirring head, which will not damage the covering film formed on the surface of aluminum alloy. Thus the scum on the surface is effectively prevented from being involved in the solution again.

The disclosure discloses a spinning process of a magnesium alloy wheel hub, which comprises the following steps: step 1, heating a magnesium alloy bar at 350-430° C. and keeping the temperature for 20 minutes; step 2, initially forging and forming on the bar under a forging press, wherein the forging down-pressing speed is 6-15 mm/s; step 3, finally forging and forming on the bar under a forging press, wherein the forging down-pressing speed is 5-8 mm/s; step 4, stress relief annealing on the final forged magnesium alloy blank; step 5, solid dissolving on the annealed magnesium alloy blank; step 6, taking out the solid-dissolved blank and directly spinning by a spinning machine; step 7, heating treatment and aging treatment. The magnesium alloy wheel hub with excellent performance is obtained by the process, and the spinning process and processing efficiency are greatly improved.

The disclosure discloses a method for manufacturing special purpose vehicle wheels by using 7000 series aluminum alloys, comprising the following steps: step 1, smelting 7000 series aluminum alloys in a smelting furnace; step 2, making the solution obtained in step 1 into an aluminum alloy ingot blank through a spraying and forming process; step 3, extruding the aluminum alloy ingot blank of step 2 to obtain an extrusion bar; step 4, sawing the extrusion bar into blanks and heating them; step 5, rolling the blank into a cake; step 6, putting the cake into a press for forging and forming; step 7, spinning and forming the wheel rim. The wheel manufactured by the method for manufacturing special vehicle wheels with 7000 series aluminum alloys in the present disclosure has high and stable conductivity, qualified impact test and good bending and radial fatigue performance.

The disclosure discloses a magnesium alloy for wheels, comprising in mass percentage: Al: 2-3.0 wt. %; Zn: 0.5-1.0 wt. %; Mn: 0.3-0.5 wt. %; Ce: 0.15-0.3 wt. %; La: 0.05-0.1 wt. %, the balance is Mg. The magnesium alloy of the present invention takes Al element and Mn element as main alloying elements, supplemented by trace Ce and La elements as alloying process, and the nano-scale Mn-rich precipitated phase obtained during homogenization and the segregation of rare earth elements Ce and La at the interface and grain boundary of Mn-rich precipitated phase are used to inhibit the coarsening during extrusion and forging, so as to improve the strength and plastic deformation ability of the alloy.

The disclosure discloses a magnesium alloy material smelting device, comprising a furnace, a disc packing device, the disc packing device comprising a stirring shaft, a packing basket, a disc stirring head, the stirring shaft connected with a packing basket, the bottom of the packing basket connected with a disc stirring head, the disc stirring head comprising a plurality of stirring wings, the stirring wings connected with the packing basket and the stirring disc, the connecting ends of the stirring wings connected with each other, the stirring ends extending to the edge of the stirring disc, and the sidewall of the packing basket provided with a liquid passage hole; during the process of preparing and processing the magnesium alloy, the disc stirring head may accelerate the diffusion, the rotation of the disc stirring head may divide the melt into upper and lower layers, and the upper layer of the melt forms a solution vortex to accelerate the diffusion of the master alloy elements; the lower melt keeps relatively static to avoid the upturn of precipitated slag and shorten the precipitation time of slag, thereby improving the productivity.

The disclosure discloses a high-speed spinning magnesium alloy and a preparation method thereof, the magnesium alloy has Mg—Al—Zn—Mn—Sr alloy with a high formability and high strength, and its chemical composition mass percentage is: Al: 2.4-4.5 wt. %; Zn: 0.6-1.2 wt. %; Mn: 0.4-0.6 wt. %; Sr: 0.15-0.3 wt. %; the balance is Mg. The present disclosure adopts the principle that by increasing the content of Mn in the magnesium alloy, a large amount of Mn-rich phase is generated during the alloy preparation process, and the degree of subcooling is controlled so that a fine spherical dispersed nano-scale Mn-rich phase is obtained during the solidification process. The nano-scale Mn-rich precipitate phase can pin the grain boundaries and inhibit the grain boundary migration to refine grains and achieve the effect of improving the strength. The divorced eutectic Mg 17 Al 12 phase generated during the casting process will deteriorate the structure, so Sr is added to the alloy, Sr combining with Al to suppress the coarse phase of divorced eutectic Mg 17 Al 12 , refine the grains, increase the amount of eutectic, and reduce the risk of thermal cracking of large-size cast bars. In addition, Sr weakens the texture during the high-temperature spinning forming process and reduces the risk of cracking during the spinning tension, which is beneficial to high-speed spinning forming.

The disclosure discloses a magnesium alloy material smelting device, comprising a furnace, a disc packing device, the disc packing device comprising a stirring shaft, a packing basket, a disc stirring head, the stirring shaft connected with a packing basket, the bottom of the packing basket connected with a disc stirring head, the disc stirring head comprising a plurality of stirring wings, the stirring wings connected with the packing basket and the stirring disc, the connecting ends of the stirring wings connected with each other, the stirring ends extending to the edge of the stirring disc, and the sidewall of the packing basket provided with a liquid passage hole; during the process of preparing and processing the magnesium alloy, the disc stirring head may accelerate the diffusion, the rotation of the disc stirring head may divide the melt into upper and lower layers, and the upper layer of the melt forms a solution vortex to accelerate the diffusion of the master alloy elements; the lower melt keeps relatively static to avoid the upturn of precipitated slag and shorten the precipitation time of slag, thereby improving the productivity.

The disclosure discloses an aluminum alloy material smelting device, comprising a furnace, a cutter packing device with a stirring shaft, a packing basket, a cutter-type stirring head, the stirring shaft connected with the packing basket, the bottom of the packing basket connected with a cutter-type stirring head, the cutter-type stirring head comprising a plurality of stirring blades, one end of the stirring blades connected with the bottom of the packing basket, the other end connected with each other on the central axis of the packing basket, and the side wall of the packing basket provided with a liquid passage hole to form liquid exchange with the solution outside the packing basket; the rotation of the cutter-type stirring head forming a solution vortex to accelerate the diffusion of added elements, and the vortex only formed under the stirring head, which will not damage the covering film formed on the surface of aluminum alloy, effectively prevent the scum on the surface from being involved in the solution again, thereby ensuring the consistency of the properties and chemical composition of the prepared aluminum alloy material, and reducing the influence of aluminum alloy scum on the solution.