Al-X (X=Nb, Cr, Fe) Ultra-High Strength In-Situ Composite Wire
Al-X (X=Nb, Cr, Fe) Ultra-High Strength In-Situ Composite Wire
复制标题
Al-X（X=Nb、Cr、Fe）超高强度原位复合丝
DOI：
10.4028/www.scientific.net/msf.331-337.1133
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
H. Toda
中科院分区：
文献类型：
--
作者：
Toshiro Kobayashi;H. Toda
铸造和变形的微复合材料如Cu-Nb多元复合材料已被报道为超高强度线材，其在大变形下表现出抗拉强度的异常增加。为了将此过程应用于铝基线材，粉末冶金工艺是一种有吸引力的替代方法，以避免化学活性Al和二次元素之间的界面反应。本研究的目的是制备这样一种大变形的原位铝基复合丝材，并对其力学性能进行评价。拉伸强度是特别感兴趣的，特别是从与微观结构的关系的观点来看。将Al粉和Nb粉混合，单轴压制，并采用两个叠层步骤进行型锻，以获得高拉伸应变。包括压制在内的所有过程都在室温空气中进行。随着拉伸应变的增加，金属丝变得更细、更紧密，并且丝分布的均匀性也随着变形而增加。当拉伸应变为14.6时，拉伸强度增加至1063 MPa，这是本研究中的最大拉伸应变。研究了复合材料的极限拉伸强度与平均纤维间距的关系。与Hall-Petch型关系有很好的相关性。这一结果表明，细丝作为障碍，对位错运动，和第二相障碍的剪切模量是一个主要的参数，为加强线。
Cast and deformed microcomposites such as Cu-Nb multifilamentary composites have been reported as ultra-high strength wires which exhibits anomalous increase in tensile strength with heavy deformation. To apply this procedure to aluminum based wires, powder metallurgy process is an attractive alternative to avoid interfacial reaction between chemically reactive Al and secondary elements. The present study is aimed at fabrication of such a heavily deformed in-situ composite wire based on Al and evaluation of its mechanical properties. Tensile strength is of particular interests, especially from the viewpoint of relationship with microstructures. Al powder and Nb powder are mixed, uni-axially pressed, and swaged with two restacking steps employed to obtain high drawing strain. All processes including the pressing are performed in room temperature air. Metal filaments get finer and closer together as the drawing strain increases, and uniformity of the filament distribution also increases with deformation. Tensile strength increases to 1063 MPa at drawing strain of 14.6, which is the maximum drawing strain in this study. The dependence of ultimate tensile strengths of the composites on the mean filamentary spacing is investigated. There is a good correlation with the Hall-Petch type relationship. This result suggests that the filaments acts as barriers against dislocation motion, and that shear modulus of the second phase barrier is a predominant parameter for the strengthening of the wire.