(蘭州理工大學(xué) 甘肅省有色金屬新材料重點(diǎn)實(shí)驗(yàn)室, 蘭州 730050)
摘 要: 分別用小通道角模具(模具Ⅰ)和大通道角模具(模具Ⅱ)以及A 路徑和Bc路徑對(duì)單晶銅和多晶銅進(jìn)行等通道角擠壓(ECAP)實(shí)驗(yàn)，對(duì)擠壓后的組織進(jìn)行光學(xué)顯微鏡(OM)和掃描電鏡(SEM)觀察，對(duì)擠壓后的單晶銅組織進(jìn)行XRD分析，研究單晶銅和多晶銅在擠壓中的變形行為。結(jié)果表明：?jiǎn)尉с~在兩種路徑擠壓后的抗拉強(qiáng)度無(wú)明顯差異，用模具Ⅰ擠壓時(shí)其力學(xué)性能的變化幅度較大，經(jīng)多道次擠壓后，其顯微組織沿壓力軸方向具有明顯的定向排列特征。多晶銅在A路徑擠壓時(shí)，其抗拉強(qiáng)度的上升幅度明顯比在Bc路徑擠壓時(shí)大。隨著擠壓道次的增加，兩種材料的組織均勻化程度和硬度增大，其斷裂方式逐漸由韌性斷裂向脆性斷裂方向轉(zhuǎn)變。
關(guān)鍵字: 單晶銅；多晶銅；等通道角擠壓；大塑性變形；力學(xué)性能
polycrystalline copper during super plastic and cyclic deformation
（State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology,
Lanzhou 730050, China）
Abstract:The mechanical properties of single crystal copper and polycrystalline copper were investigated by equal channel angular pressing (ECAP) through two die channels with small angles (DieⅠ) and larger angles (Die Ⅱ), and on route A and route Bc. The microstructures of extruded samples were observed with optical microscopy(OM) and scanning electron microscopy(SEM), and the microstructures of single crystal copper during extrusion were analyzed by X-ray diffractometry(XRD). The deformation behaviors of single crystal copper and polycrystalline copper during extrusion were studied. The results show that the tensile strengths of single crystal copper extruded samples on route A increase faster than those on route Bc, and the difference between them first increases and then decreases. The mechanical properties of single crystal copper change quickly during extrusion with die Ⅰ. The microstructure of single crystal copper has obvious orientational characteristics along the forcing spindle after several extruding passes. During extrusion, the tensile strength of polycrystalline copper on route A increases more significantly than that on route Bc. With increasing the extrusion passes, the uniformity of the two kinds of materials improves and the hardness increases, and the mode of fracture changes gradually from ductile fracture to brittle fracture.
Key words: single crystal copper; polycrystalline copper; equal channel angular pressing; super plastic deformation; mechanical property
