沉淀硬化型铁素体ODS合金近终形制备的基础问题

氧化物弥散强化铁素体合金（简称铁素体ODS合金）具有优异的高温力学性能，良好的抗辐照和抗氧化性能，密度较低，是核能、航空航天、国防装备等高技术领域不可替代的关键材料。本项目针对该合金中温强度不足和难成形问题，提出了采用金属间化合物沉淀相提升铁素体ODS合金中温强度，并以选区激光熔化3D打印技术实现高性能ODS合金近终形制造的新思路。重点研究碳负载纳米氧化物粒子合成与组装、近球形铁基粉末-氧化物粒子复合粉制备原理与方法，微熔池形态对氧化物粒子运动规律和缺陷的影响，沉淀相和合金显微组织各向异性形成规律与调控，合金强韧性匹配等关键科学和技术问题，为建立高性能ODS合金的近终形制备技术奠定理论和技术基础。

Oxide dispersion strengthened ferritic alloy (ferritic ODS) demonstrates excellent high temperature mechanical properties, high irradiation and oxidation resistance, and relatively low density, which is irreplaceable material in the area of nuclear energy, aeronautical and space, as well as national defense. In view of the lack of intermediate temperature strength and the forming difficulty, the new idea was proposed that the intermediate temperature strength of the ferritic ODS alloy was enhanced by intermetallic precipitates, and near-net shape forming was achieved by 3D printing technology of selected laser melting. The main focus was on the investigation of the synthesis and assembly of carbon-loaded nano-oxide particles, the principle and method of the preparation of near spherical iron-nano oxide composite particles, the influence of micro molten pool on oxide dispersion and pore defects, the accurately control of intermetallic precipitates and microstructural anisotropy, as well as the matching between strength and ductility of the ferritic ODS alloy. The theory and technical fundaments for the near-net shape forming of high performance ODS alloy are expected to be established.