Paradox of strength and ductility in metals processed by severe plastic deformation
Paradox of strength and ductility in metals processed by severe plastic deformation
复制标题
剧烈塑性变形加工金属中强度与延展性的矛盾关系
DOI：
10.1557/jmr.2002.0002
复制
发表时间：
2002-01-01
影响因子：
2.7
通讯作者：
Lowe, TC
中科院分区：
文献类型：
--
作者：
Valiev, RZ;Alexandrov, IV;Lowe, TC
众所周知，由常规成形方法如轧制、拉拔或挤压引起的塑性变形可以显著提高金属的强度，然而，这种提高通常伴随着延展性的损失。例如，图1显示，随着塑性变形的增加，Cu和Al的屈服强度单调增加，而它们的断裂伸长率（延展性）降低。同样的趋势也适用于其他金属和合金。在这里，我们报告了一个非凡的高强度和高延展性的组合产生的金属受到严重的塑性变形（SPD）。我们认为，这种不寻常的机械行为是由SPD加工产生的独特纳米结构引起的。超细晶粒尺寸和高密度位错的组合似乎使新的机制变形。这项工作证明了通过SPD定制金属和合金的微观结构以获得高强度和高延展性的可能性。具有这种理想的机械性能的材料对于先进的结构应用是非常有吸引力的。
It is well known that plastic deformation induced by conventional forming methods such as rolling, drawing or extrusion can significantly increase the strength of metals However, this increase is usually accompanied by a loss of ductility. For example, Fig. 1 shows that with increasing plastic deformation, the yield strength of Cu and Al monotonically increases while their elongation to failure (ductility) decreases. The same trend is also true for other metals and alloys. Here we report an extraordinary combination of high strength and high ductility produced in metals subject to severe plastic deformation (SPD). We believe that this unusual mechanical behavior is caused by the unique nanostructures generated by SPD processing. The combination of ultrafine grain size and high-density dislocations appears to enable deformation by new mechanisms. This work demonstrates the possibility of tailoring the microstructures of metals and alloys by SPD to obtain both high strength and high ductility. Materials with such desirable mechanical properties are very attractive for advanced structural applications.