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 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 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.