高密度电脉冲下材料微观结构的演变  

ELECTROPULSING-INDUCED EVOLUTION OF MICROSTRUCTURES IN MATERIALS

作　　者：张伟[1] 隋曼龄[1] 周亦胄[1] 何冠虎[1] 郭敬东[1] 李斗星[1] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016

出　　处：《金属学报》2003年第10期1009-1018,共10页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目90206044;50271074;50125103;科技部国家重点基础研究发展规划项目2002CB613503资助

摘　　要：几种粗晶材料经高密度电脉冲处理后,在材料内部形成了局域纳米结构,即冷轧α-Cu(Zn)中形成α—Cu(Zn)和β-(CuZn)纳米相;低碳钢中形成纳米尺寸的奥氏体;TiC/Ni(Cr)金属陶瓷中形成纳米尺寸的定向TiC;LC6超硬铝中形成纳米尺寸的α—Al.粗晶纳米化转变的机制可归于电脉冲下多种因素的竞争,包括高速加热、热应力、削减的热力学势垒和较大的电子冲击力等.另外,电脉冲处理后的黄铜和金属陶瓷中分别形成了许多低能的位错组态、大量的层错和孪晶.这类缺陷结构演变与电脉冲输入的电能、热能和应力有关.Nanostructures can form in several conventional materials under high current density electropulsing, for example, nanophases of alpha-Cu(Zn) and beta'-(CuZn) in a cold-worked alpha-Cu(Zn) alloy, nanosized gamma-Fe in a low-carbon steel, orientated nanosized TiC in a TiC/Ni(Cr) cermet and nanosized alpha-Al in an LC6 superduralumin. The mechanisms responsible for the above nanostructured transitions can be attributed to the competition of many factors induced by electropulsing, including high-rate heating, thermal stress, reduced thermodynamics barrier and large electron impacting. On the other hand, many low-energy dislocation configurations, large amounts of twins and stacking faults form in the brass and cermet under the electropulsing. The evolution of the above defects is closely associated with the electrical energy, thermal energy and the stress introduced by the electropulsing.

关 键 词：电脉冲 纳米结构 位错 孪晶 

分 类 号：O77[理学—晶体学]