低浓度Cu-Al_2O_3弥散强化铜合金拉伸断裂特性的研究  

Fracture characteristics of low alumina concentration Cu-Al_2O_3 alloy

作　　者：郭明星[1] 汪明朴[1] 李周[1] 曹玲飞[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《材料热处理学报》2007年第1期105-109,共5页Transactions of Materials and Heat Treatment

基　　金：国家高新技术发展"863"计划资助项目(2002AA302505);湖南省自然科学基金(05JJ30095)

摘　　要：通过力学性能测量、金相以及SEM观察对不同状态低浓度Cu-0.23vol%Al2O3弥散强化铜合金的断裂行为进行了研究。结果表明:合金经过单向冷轧变形后,无论是冷轧态还是退火态纵向强度、伸长率均高于横向。纵向工程应力-应变曲线仅发生一次断裂,但是横向工程应力-应变曲线却出现“二次断裂”现象。出现“二次断裂”现象的原因可能是,经冷轧变形后的弥散强化铜合金组织呈纤维状,而纤维界面为弱结合面,裂纹易于在界面上形成和扩展,在横向拉应力作用下极易导致几层纤维组织优先被“劈开”,出现“一次断裂”;在继续拉伸过程中其他部位不断“劈开”,合金的工程应力-应变曲线出现“二次断裂”现象,并给出了纵横向拉伸断裂模型图。The fracture of low alumina concentration dispersion strengthened copper alloy（ADSCA） under different conditions was studied by mechanical property tests, OM and SEM observation. The results show that the longitudinal strength and elongation of alumina dispersion strengthened copper alloy （ADSCA） cold rolled in unidirection are higher than that of transverse values for both cold rolling and annealing states. Pop-in phenomenon can be observed for the transverse stress-strain curves possibly due to the fibrous mierostrueture of ADSCA cold rolled and cracks easily form and grow on the fibrous boundary. As the boundary is weak-bonded boundary, several fibrous layers are easy to be ＂splited＂ with the transverse tensile load, and ＂primary fracture＂ occurs. With the continuation of transverse tension, the other regions are ＂splited＂, and thus the pop-in appears on the transverse engineering stress-strain curve. In order to clearly compare the difference of longitudinal and transverse tensile fracture, the tensile fracture models are given based on the experiment.

关 键 词：弥散强化铜合金(DSCA) 冷轧 退火 二次断裂 

分 类 号：TG146.1[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]