(1. 昆明理工大學(xué) 材料科學(xué)與工程學(xué)院，昆明 650093； 2. 昆明理工大學(xué) 金屬先進(jìn)凝固成形及裝備技術(shù)國家地方聯(lián)合工程實(shí)驗(yàn)室，昆明 650093)
摘 要: 對采用嚴(yán)重塑性變形方法制備的超細(xì)晶金屬進(jìn)行退火處理，是提高該類材料綜合性能的常見方法。為保證晶粒不發(fā)生明顯長大，對累積疊軋(ARB)方法制備的超細(xì)晶純銅在100 ℃(低于再結(jié)晶溫度)時(shí)進(jìn)行退火處理，研究保溫時(shí)間對ARB超細(xì)晶銅室溫拉伸斷裂行為的影響以及樣品的微觀結(jié)構(gòu)、力學(xué)行為、斷口形貌，并對其力學(xué)性能和斷裂機(jī)制進(jìn)行分析。結(jié)果表明：當(dāng)退火時(shí)間為30 min時(shí)，ARB超細(xì)晶銅的屈服強(qiáng)度和抗拉強(qiáng)度都達(dá)到退火態(tài)的極大值。斷口的大量韌窩表明：退火時(shí)間30 min時(shí)的材料具有一定的塑性變形能力，斷裂機(jī)制以韌性斷裂為主，因此，退火時(shí)間為30 min時(shí)，ARB超細(xì)晶銅的強(qiáng)度與塑性達(dá)到最佳匹配。
關(guān)鍵字: 累積疊軋超細(xì)晶銅；預(yù)退火；微觀結(jié)構(gòu)；力學(xué)行為；斷口形貌；室溫
（1. School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China; 2. National and Local Joint Engineering Laboratory of Advanced Metal Solidification Forming and Equipment Technology (Yunnan), Kunming University of Science and Technology, Kunming 650093, China）
Abstract:Preparing ultrafine grained (UFG) materials by annealing treatment is a common method to improve the plasticity of severe plastic deformation (SPD) materials. The ultrafine grained pure Cu prepared by accumulative rolling bonding (ARB) method at 100 ℃ (below the recrystallization temperature) was annealed in order to ensure that the grain does not grow obviously. The effect of different holding time on the tensile deformation behavior of ARB-Cu at room temperature was investigated. The microstructures, the fracture morphologies and the mechanical curves of ARB-Cu were analyzed, the mechanical property and the microscopic fracture mechanism were discussed. The results show that, when the annealing time is 30 min, the yield strength, the tensile strength and the plastic all reach the maximum of the annealed states. The number of dimple can be known that it has certain plastic deformation ability, the fracture mechanism is ductility fracture. In conclusion, the strength and plasticity of the annealing time 30 min reach the best match.
Key words: accumulative rolling bonding ultrafine grained Cu; pre-annealing; microstructure; mechanical property; fracture morphology; room temperature
