Abstract: A method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles is provided. In the method, a nickel-based superalloy is used as a matrix, and one or more of TiC, TiB2, WC and Al2O3 are used as a strengthening phase. A ceramic particle raw material used as the strengthening phase has a particle size of 1-5 ?m and is added in an amount of 1-5 wt. %. A nickel-based superalloy composite powder having homogeneously distributed nano-scale ceramic is prepared by mechanical milling. A nano-scale ceramic phase strengthened nickel-based superalloy is prepared by 3D printing technology, which has a homogeneously distributed nano-scale ceramic phase and excellent mechanical properties.

Abstract: A high-strength Al-Cu-Mg-Mn aluminum alloy and a preparation method therefor is provided. The alloy includes the following components in percentage by weight: Si:?0.5%, Fe: ?0.5%, Cu: 4.5-6.3%, Mg: 0.6-1.2%, Mn: 0.6-1.5%, Sc: 0.15-0.35%, Zr: 0.1-0.2%, and Y: 0.1-0.3%, the balance being aluminum and non-removable impurities. The preparation method includes: smelting, refining, impurity removing and degassing, pouring, homogenizing heat treatment, three-dimensional large deformation forging pre-deformation, isothermal deformation processing, and heat treatment. A casting mold used is a special combined mold having a metal mold as an inner mold, a surrounding cooling pipe, and a sand mold as an outer mold, and is used to prepare and obtain high-quality, high-performance castings. The heat treatment is solid solution treatment plus gradient aging treatment.

Abstract: A method for preparing a nano spherical oxide dispersion strengthening phase using a micron oxide is proposed for the first time. First, a micron oxide is used as a raw material to prepare a nano oxide with a completely amorphous structure/matrix alloy composite powder by mechanical ball milling in stages. In the first stage, ball milling is performed, causing the oxide to break and transform in structure, and achieving nano-sizing and completely amorphization, to prepare a composite powder with a completely amorphous structure nano oxide uniformly distributed in the matrix alloy powder; and in the second stage, the composite powder obtained in the first stage and the remaining matrix alloy powder are uniformly mixed by ball milling. Then, the uniformly mixed powder is sequentially subjected to hot forming, hot rolling, and heat treatment, to obtain a nano spherical oxide dispersion strengthened alloy.

Abstract: A method for preventing cracking of nickel-based superalloy fabricated by selective laser melting (SLM) belongs to the field of additive manufacturing (AM). The method of preparing an as-built part with a high density, no crack defects, and good mechanical properties includes: reducing the content of elements Zr and B forming low melting point phase in a nickel-based superalloy, adjusting the total content of Al and Ti in the alloy to 4.5 wt % or below, and combining with the control of special SLM process parameters. The new method has the advantages of a reasonable component design, a simple preparation process, and good performance of the as-built part, and therefore is suitable for large-scale application.

Abstract: A nickel-based superalloy for three-dimension (3D) printing and a powder preparation method thereof are provided. The method of preparing the nickel-based superalloy and its powder includes: RE microalloying combined with vacuum melting, degassing, refining, atomization with reasonable parameters, and a sieving process. The new method significantly reduces the cracking sensitivity of the “non-weldable” PM nickel-based superalloys, and broadens the 3D printing process window. The as-printed part has no cracks, and good mechanical properties. In addition, the powder prepared by the new method has higher sphericity and better flowability, and less irregular powders. The yield of fine powders with a particle size of 15-53 ?m and medium-sized powders with a particle size of 53-106 ?m that are required for 3D printing is greatly improved, which meet the requirements for 3D printing of high-quality, low-cost nickel-based superalloy powder.