This pure copper plate or sheet contains 99.96% by mass or greater of Cu, in which when an average crystal grain size of crystal grains in a rolled surface is represented by X μm and an amount of Ag is represented by Y mass ppm, an expression of 1×10.sup.−8≤X.sup.−3Y.sup.−1≤1×10.sup.−5 is satisfied, and when a ratio of J3, in which all three grain boundaries constituting a grain boundary triple junction are special grain boundaries, to all grain boundary triple junctions is defined as NF.sub.JE and a ratio of J2, in which two grain boundaries constituting a grain boundary triple junction are special grain boundaries and one grain boundary constituting the grain boundary triple junction is a random grain boundary, to all grain boundary triple junctions is defined as NF.sub.J2, an expression of 0.30<(NF.sub.J2/(1−NF.sub.J3)).sup.0.5≤0.48 is satisfied.

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.

A variable stiffness engineered degradable ball or seal having a degradable phase and a stiffener material. The variable stiffness engineered degradable ball or seal can optionally be in the form of a degradable diverter ball or sealing element which can be made neutrally buoyant.

A variable stiffness engineered degradable ball or seal having a degradable phase and a stiffener material. The variable stiffness engineered degradable ball or seal can optionally be in the form of a degradable diverter ball or sealing element which can be made neutrally buoyant.

The present invention relates to the technical field of manufacturing of metal materials, and in particular to a 7000-series aluminum alloy wire for additive manufacturing and a preparation method thereof. The wire was prepared by subjecting an Al—Ti—B intermediate alloy containing TiB.sub.2 particles generated in situ to severe plastic deformation to obtain an intermediate alloy containing TiB.sub.2 nanoparticles having a particle size of 50-1,000 nm or a mixture of two different particles; using the intermediate alloy containing TiB.sub.2 nanoparticles as a matrix raw material, adding other metal or intermediate alloy for smelting to obtain an alloy melt; preparing a wire blank with the alloy melt; subjecting the wire blank to hot rolling, drawing, intermediate annealing and surface treatment to obtain an Al—Zn—Mg—Cu alloy wire reinforced by particles at nano scale or submicron scale.

The present invention relates to the technical field of manufacturing of metal materials, and in particular to a 7000-series aluminum alloy wire for additive manufacturing and a preparation method thereof. The wire was prepared by subjecting an Al—Ti—B intermediate alloy containing TiB.sub.2 particles generated in situ to severe plastic deformation to obtain an intermediate alloy containing TiB.sub.2 nanoparticles having a particle size of 50-1,000 nm or a mixture of two different particles; using the intermediate alloy containing TiB.sub.2 nanoparticles as a matrix raw material, adding other metal or intermediate alloy for smelting to obtain an alloy melt; preparing a wire blank with the alloy melt; subjecting the wire blank to hot rolling, drawing, intermediate annealing and surface treatment to obtain an Al—Zn—Mg—Cu alloy wire reinforced by particles at nano scale or submicron scale.

Described herein are additive manufacturing methods and products made using such methods. The alloy compositions described herein are specifically selected for the additive manufacturing methods and provide products that exhibit superior mechanical properties as compared to their cast counterparts. Using the compositions and methods described herein, products that do not exhibit substantial coarsening, such as at elevated temperatures, can be obtained. The products further exhibit uniform microstructures along the print axis, thus contributing to improved strength and performance. Additives also can be used in the alloys described herein.

Described herein are additive manufacturing methods and products made using such methods. The alloy compositions described herein are specifically selected for the additive manufacturing methods and provide products that exhibit superior mechanical properties as compared to their cast counterparts. Using the compositions and methods described herein, products that do not exhibit substantial coarsening, such as at elevated temperatures, can be obtained. The products further exhibit uniform microstructures along the print axis, thus contributing to improved strength and performance. Additives also can be used in the alloys described herein.

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.