(北京科技大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083)
摘 要: 通過(guò)下引式連續(xù)定向凝固設(shè)備，調(diào)控合理的工藝參數(shù)制備出表面光潔、單一á100？取向的柱狀晶銅桿。然后經(jīng)室溫拉拔(不經(jīng)過(guò)中間熱處理)，表現(xiàn)出超延展變形。通過(guò)組織觀察和性能分析，發(fā)現(xiàn)其塑性變形可以分為3個(gè)階段：一般硬化階段(ε≤4.13)，低硬化速率階段(4.13≤ε≤10.16)，部分亞微米等軸晶粒形成階段(ε≥10.16)。每個(gè)階段的塑性變形行為各有不同，各有其特點(diǎn)。研究結(jié)果全面地概括連續(xù)柱狀晶組織銅桿在室溫拉拔過(guò)程中的變形機(jī)理，同時(shí)也為超細(xì)銅絲的制備提供必要的理論依據(jù)。
關(guān)鍵字: 銅桿；連續(xù)柱狀晶組織；超延展變形；低硬化速率；亞微米等軸晶
（School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The smooth surface and single á100？ oriented columnar-grained copper rods were prepared by downward continuous unidirectional solidification equipments with reasonable process parameters, then, the copper rods were drawn at ambient temperature (without intermediate heat treatment), which exhibits the extreme plastic extensibility. The results show that the plastic deformation of the copper rod can be divided into three different stages by observation of its microstructure and properties, general hardening stage (ε≤4.13), low hardening rate stage (4.13≤ε≤10.16). Some submicron equiaxed grain forming stage (ε≥10.16). Each stage of the plastic deformation behavior is different and has its own characteristics. Not only the drawing mechanism of continuous columnar-grained copper rods at ambient temperature was comprehensively summarized, but also the necessary theoretical basis for the preparation of ultrafine copper wire was provided.
Key words: copper rod; continuous columnar grains; extreme plastic extensibility; low hardening rate; submicron equiaxed grain
