中文摘要：

金属Cu中孪晶的作用已受到广泛关注。介绍了孪晶的分类及晶体学结构,综述了孪晶对Cu强度、塑性、加工硬化、应变速率敏感性、变形机制和电阻率（或电导率）等方面的影响规律及内在机理,讨论了孪晶Cu研究的不足之处及需要加强的方面,并指出通过适当的工艺技术,在晶粒中引入高密度的孪晶同时获得高强度、高塑性和良好电导性能,将是未来发展高性能工程用Cu及其合金的重要方向。

英文摘要：

Much attention is paid on the twins in pure Cu.The classification and crystallographic structure of twins are introduced.The effect of twins on strength,ductility,strain hardening,strain rate sensitivity,plastic deformation mechanism and electrical resistivity（or conductivity） is summarized,and the mechanisms underlying these phenomena are discussed.At the same time,it is discussed what should be studied further in the Cu with twins.It is eventually pointed out that introducing high density of twins in grains by using proper preparation technique could obtain high strength,improved ductility as well as good conductivity,and it should be also a noteworthy research direction for developing high performance engineering Cu and its alloys in the future.