中國有色金屬學(xué)報(bào)
ZHONGGUO YOUSEJINSHU XUEBAO
| 第18卷 第11期 總第116期 2008年11月 |
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文章編號：1004-0609(2008)11-1995-07
藕狀多孔銅軸向壓縮變形行為與本構(gòu)關(guān)系
姚 迪，劉新華，劉雪峰，謝建新
(北京科技大學(xué) 新材料技術(shù)研究院，北京 100083)
摘 要: 在氫氣壓力為0.2 MPa、熔體溫度為1 200 ℃條件下采用定向凝固法制備d 45 mm×120 mm的藕狀多孔純銅棒材，研究藕狀多孔金屬的壓縮變形過程及其影響因素，分析藕狀多孔材料的壓縮變形機(jī)理，采用線性回歸分析方法建立藕狀多孔材料的壓縮變形本構(gòu)關(guān)系。結(jié)果表明：藕狀多孔銅的壓縮變形過程分為彈性變形、以孔壁塑性屈曲為主的大塑性變形和密實(shí)化3個(gè)階段；大塑性變形階段的主要變形機(jī)理是孔壁先呈波形彎曲，然后產(chǎn)生塌陷和折疊變形；藕狀多孔銅沿平行氣孔方向靜態(tài)壓縮時(shí)應(yīng)力—應(yīng)變曲線受應(yīng)變速率影響很小。
關(guān)鍵字: 藕狀多孔金屬；定向凝固；變形行為；本構(gòu)關(guān)系
Axial compressive deformation behaviors and constructive relation for lotus-type porous copper
YAO Di, LIU Xin-hua, LIU Xue-feng, XIE Jian-xin
（Advanced Materials and Technologies Institute, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Lotus-type porous copper bars of 45 mm in diameter and 120 mm in length were fabricated by unidirectional solidification at hydrogen pressure of 0.2 MPa and molten temperature of 1 200 ℃. The compressive deformation process and its effect factors were investigated. The deformation mechanism of lotus-type porous copper was also analyzed and discussed. The compressive mechanical model of lotus-type porous metals was established using the method of linear regression. The results show that the deformation of lotus-typed porous copper consists of three stages of elastic deformation, large plastic yield deformation with mainly pore wall buckling, collapse and densification. The main deformation mechanism in the large plastic deformation stage is that the pore walls buckle in a periodic wave and then collapse and fold. The strain rate has little effect on the compressive stress parallel to the direction of pores.
Key words: lotus-type porous metal; unidirectional solidification; deformation behaviors; constitutive relation
