A piece of jewelry has a copper-containing gold alloy which consists of 75.0 to 75.2 wt. % gold, 16.5 to 17.0 wt. % copper, 3.1 to 7.1 wt. % silver, 1.2 to 3.2 wt. % palladium, and a remainder containing 0.5 to 2.5 wt. % zinc.

An improved aluminum alloy for blending with a recycled aluminum alloy to form a material for high pressure vacuum die casting is provided. The improved aluminum alloy includes 10 to 12 wt. % silicon, 0.65 to 0.85 wt. % manganese, less than 0.05 wt. % iron, less than 0.05 wt. % magnesium, 0.2 to 0.4 wt. % strontium, less than 0.05 wt. % titanium, and less than 0.02 wt. % copper, based on the total weight of the improved aluminum alloy. The recycled aluminum alloy typically includes 0.60-1.0 wt. % silicon, ≤0.35 wt. % iron, ≤0.20 wt. % copper, 0.05-0.20 wt. % manganese, 0.40-0.8 wt. % magnesium, ≤0.20 wt. % chromium, ≤0.15 wt. % zinc, ≤0.05 wt. % titanium, ≤0.05 wt. % others (each), and ≤0.15 wt. % others (total). The material meets the specifications for an Aural 5S alloy.

The present invention relates to techniques for producing 2024 and 7075 aluminum alloys by recycling waste aircraft aluminum alloys, which belong to technical fields for circular economy. The present invention develops techniques for obtaining the 2024 and 7075 aluminum alloys by subjecting waste aircraft aluminum alloys as raw materials to pretreatment, smelting, impurity removal, melt ingredient assay, ingredient adjustment, refining, and casting. Through utilizing the waste package aluminum alloys and the waste aluminum pop-top cans to adjust the ingredients, the waste aircraft aluminum alloys would be recycled at a lower cost without downgrading. The present invention has some advantages, such as low cost, and applicability for industrial production, as well as prominent economic benefit.

The present invention relates to techniques for producing 2024 and 7075 aluminum alloys by recycling waste aircraft aluminum alloys, which belong to technical fields for circular economy. The present invention develops techniques for obtaining the 2024 and 7075 aluminum alloys by subjecting waste aircraft aluminum alloys as raw materials to pretreatment, smelting, impurity removal, melt ingredient assay, ingredient adjustment, refining, and casting. Through utilizing the waste package aluminum alloys and the waste aluminum pop-top cans to adjust the ingredients, the waste aircraft aluminum alloys would be recycled at a lower cost without downgrading. The present invention has some advantages, such as low cost, and applicability for industrial production, as well as prominent economic benefit.

A preparation method of a high-strength and high-toughness A356.2 metal matrix composites for a hub is provided, including the following preparation process steps: preparation of a (graphene+HfB.sub.2)-aluminum master alloy wire; A356.2 alloy melting, master alloy addition, refining, and pressure casting; solution and aging treatment; shot blasting, finishing, alkaline/acid cleaning, anodic oxidation, and finished product packaging. In this way, two systems of two-dimensional nano-structure graphene nucleation and in-situ self-nucleation are introduced to complement each other, a second phase of silicon in A356.2 is refined by multi-dimensional scaling, and multi-dimensional nano-phases strengthen the aluminum-based composite material simultaneously. The preparation method solves the problems of limiting the strength, hardness, plasticity and toughness during the application of common A356.2 alloys for a hub, and a graphene/HfB.sub.2/aluminum composite material produced by a low-pressure casting process has an excellent comprehensive performance, so as to achieve a further weight reduction requirement for light weight.

A preparation method of a high-strength and high-toughness A356.2 metal matrix composites for a hub is provided, including the following preparation process steps: preparation of a (graphene+HfB.sub.2)-aluminum master alloy wire; A356.2 alloy melting, master alloy addition, refining, and pressure casting; solution and aging treatment; shot blasting, finishing, alkaline/acid cleaning, anodic oxidation, and finished product packaging. In this way, two systems of two-dimensional nano-structure graphene nucleation and in-situ self-nucleation are introduced to complement each other, a second phase of silicon in A356.2 is refined by multi-dimensional scaling, and multi-dimensional nano-phases strengthen the aluminum-based composite material simultaneously. The preparation method solves the problems of limiting the strength, hardness, plasticity and toughness during the application of common A356.2 alloys for a hub, and a graphene/HfB.sub.2/aluminum composite material produced by a low-pressure casting process has an excellent comprehensive performance, so as to achieve a further weight reduction requirement for light weight.

The invention relates to a method for preparing amorphous particle-modified magnesium alloy surface-gradient composites and pertains to the technical field of composites. The method comprises steps of: holding the temperature at 150˜350° C. for FeCrMoBC amorphous alloy particles; mixing pure magnesium, pure zinc, pure aluminum, pure copper and Mg-5 wt % Mn alloy under continuous protective gases, gradually raising temperature to 720˜760° C. and melting at a constant temperature for 15˜25 min to obtain a magnesium alloy melt; cooling the magnesium alloy melt to 600˜635° C. and starting mechanical stirring; continuing the cooling until the semi-solid temperature is 570˜615° C., slowly adding the above FeCrMoBC amorphous alloy particles, holding for 2˜5 min after mixing evenly, and cooling the crucible with water to obtain an amorphous particle-modified magnesium alloy surface-gradient composite.

The invention relates to a method for preparing amorphous particle-modified magnesium alloy surface-gradient composites and pertains to the technical field of composites. The method comprises steps of: holding the temperature at 150˜350° C. for FeCrMoBC amorphous alloy particles; mixing pure magnesium, pure zinc, pure aluminum, pure copper and Mg-5 wt % Mn alloy under continuous protective gases, gradually raising temperature to 720˜760° C. and melting at a constant temperature for 15˜25 min to obtain a magnesium alloy melt; cooling the magnesium alloy melt to 600˜635° C. and starting mechanical stirring; continuing the cooling until the semi-solid temperature is 570˜615° C., slowly adding the above FeCrMoBC amorphous alloy particles, holding for 2˜5 min after mixing evenly, and cooling the crucible with water to obtain an amorphous particle-modified magnesium alloy surface-gradient composite.

The present application provides a solid metal material quickly soluble in water, comprising components of magnesium, gadolinium, yttrium, praseodymium, neodymium, platinum, hafnium, nickel, potassium, and manganese in a specific proportion. Furthermore, the solid metal material quickly soluble in water further comprises aluminum, copper, calcium, iron, zinc, and sodium. The present application also provides a preparation method for the solid metal material quickly soluble in water. The solid metal material quickly soluble in water provided by the present application is a quickly soluble magnesium alloy material capable of adapting to the waiting time requirement of the public for washing, can be hydrolyzed, and can react with water in a washing machine, and is environmentally friendly. Washing substances remaining on the clothes have no irritation to human skin contact, and the washing and discharging sewage discharged after washing has no harm to the environment.

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.