Bimodally grained high-strength Fe fabricated by mechanical alloying and spark plasma sintering
Bimodally grained high-strength Fe fabricated by mechanical alloying and spark plasma sintering
复制标题
DOI：
10.1016/j.actamat.2009.03.034
复制
发表时间：
2009-06
期刊：
影响因子：
9.4
通讯作者：
B. Srinivasarao;K. Oh-ishi;T. Ohkubo;K. Hono
中科院分区：
文献类型：
--
作者：
B. Srinivasarao;K. Oh-ishi;T. Ohkubo;K. Hono
采用机械球磨和放电等离子烧结工艺制备了含有一定比例粗晶和纳米氧化物弥散相的纳米晶铁。烧结样品具有2100 MPa的高拉伸强度和5%的延展性;通过优化烧结条件，可以调整强度-延展性平衡。最佳烧结条件下材料的抗拉强度为1500 MPa，伸长率为15%。微观结构由纳米晶（<100 nm）和粗晶（>1μm）组成，纳米氧化铬颗粒（<10 nm）均匀分散。强度和伸长率表现出强烈的依赖性的粗晶粒的体积分数，和高强度可以归因于纳米晶粒区域的超细晶粒尺寸和沉淀硬化的氧化物弥散体。延展性被认为是由于粗晶粒的存在。
Nanocrystalline iron containing a certain fraction of coarse grains with nanosized oxide dispersoids has been processed by mechanically milling Fe powder and subsequent spark plasma sintering. Sintered samples exhibited a high tensile strength of 2100MPa with 5% ductility; by optimizing the sintering conditions, it was possible to tune the strength–ductility balance. The optimally sintered material showed a tensile strength of 1500MPa and 15% elongation. The microstructure consists of nanograined (<100nm) as well as coarse-grained regions (>1μm) with uniform dispersion of nanosized chromium oxide particles (∼10nm). The strength and elongation show strong dependence on the volume fraction of the coarse grains, and the high strength can be attributed to the ultrafine grain size of the nanograined regions and precipitation hardening by the oxide dispersoids. The ductility is considered to be due to the presence of coarse grains.