A comparison study on microstructures and fracture behaviours of a single NbSS solid solution alloy and a two-phase NbSS/Nb5Si3 alloy prepared by spark plasma sintering and arc melting
A comparison study on microstructures and fracture behaviours of a single NbSS solid solution alloy and a two-phase NbSS/Nb5Si3 alloy prepared by spark plasma sintering and arc melting
复制标题
单一NbSS固溶体合金与放电等离子烧结和电弧熔炼制备的两相NbSS/Nb5Si3合金显微组织和断裂行为对比研究
DOI：
10.1016/j.matchar.2021.111259
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发表时间：
2021-06-17
影响因子：
4.7
通讯作者：
Sha, Jiangbo
中科院分区：
文献类型：
--
作者：
Liao, Junhua;Fei, Teng;Sha, Jiangbo
采用等离子旋转电极雾化技术（PREA）制备了单相Nb-SS合金（Nb-37 Ti-13 Cr-2Al-1 Si）和亚共晶成分为Nb-16 Si-24 Ti-2Al-2Cr的两相Nb-SS/Nb 5Si 3合金粉末，并对其进行了放电等离子烧结（SPS），研究了SPS和电弧熔炼（AM）两种合金的显微组织、断裂韧性、变形和断裂模式。随着晶粒尺寸的粗化，AM和SPS单一Nb-SS相合金的断裂韧性差异较小，并且以解理方式失效。对于包含超细延展/硬化Nb-SS/Nb_5Si_3显微组织的SPS两相Nb-SS/Nb_5Si_3样品，相尺寸约为1-2 μ m，由于α/2的活动位错的作用和细Nb-SS相的韧窝破坏，获得高达16.1MPa·m（1/2）的断裂韧性< 111 >。然而，AM双相Nb-SS/Nb 5Si 3显微组织具有粗化的Nb-SS相和9.6MPa·m（1/2）的低断裂韧性，这是由于< 100 >位错在{001}解理面中的移动和粗化的Nb-SS相的解理失效模式造成的。
Single Nb-SS phase alloy (Nb-37Ti-13Cr-2Al-1Si) and two-phase Nb-SS/Nb5Si3 alloy (hypoeutectic composition of Nb-16Si-24Ti-2Al-2Cr) powders prepared by the plasma rotating electrode atomization technique (PREA) were spark plasma sintered (SPS), and the microstructure, fracture toughness, deformation and fracture mode of the two SPS and arc melting (AM) alloys were characterized. With a coarsened grain size, the AM and SPS single Nb-SS phase alloy had a small difference in fracture toughness and it failed in a cleavage mode. As for the SPS two-phase Nb-SS/Nb5Si3 sample containing an ultra-fine ductile/stiffening Nb-SS/Nb5Si3 microstructure, approximately 1-2 mu m in phase size, a fracture toughness of as high as 16.1 MPa.m(1/2) was obtained, owing to operation of the active dislocation of a/2 < 111 > and dimple failure of the fine Nb-SS phase. However, the AM two-phase Nb-SS/Nb5Si3 microstructure had a coarsened Nb-SS phase and a low fracture toughness of 9.6 MPa.m(1/2), resulting from the movement of a < 100 > dislocation in the {001} cleavage planes and a cleavage failure mode of the coarsened Nb-SS phase.