(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究時(shí)效時(shí)加高強(qiáng)電場對(duì)2E12鋁合金的力學(xué)性能和微觀組織的影響，采用力學(xué)性能測試及透射電鏡檢測材料的力學(xué)性能和微觀組織，并分析電場對(duì)2E12鋁合金的作用機(jī)理。結(jié)果表明：16 kV/cm電場時(shí)效使晶內(nèi)S′相(Al2CuMg)粒子變得更加細(xì)小，電場也使T相(Al20Cu2Mn3)粒子變小，這略微降低了2E12鋁合金的屈服強(qiáng)度；加電場時(shí)效時(shí)，合金晶界上析出相細(xì)小彌散使合金的塑性提高；電場一方面能夠促進(jìn)S′相的形核，另一方面也能抑制其長大和粗化；空位擴(kuò)散時(shí)，電場影響了空位周邊的勢場，使空位傾向于朝電場強(qiáng)度的反方向運(yùn)動(dòng)。
關(guān)鍵字: 2E12鋁合金；電場；時(shí)效；力學(xué)性能；微觀結(jié)構(gòu)
microstructures of 2E12 aluminum alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The influence of electric field aging on the mechanical properties and microstructures of 2E12 aluminum alloy was investigated by means of mechanical tests and transmission electron microscopy (TEM). The mechanism of the effect of an electric field was analyzed. The results show that the S′ phase(Al2CuMg) particles and T phase(Al20Cu2Mn3) particles are smaller after 16 kV/cm electric field aging, which decreases the yield strength of the alloy. Meanwhile, the grain boundaries of the specimen aged in electric field are composed by numerous ultra micro precipitates, and the ductility of the alloy is improved. The electric field can accelerate the nucleation of the new phase S′, while the coarsening of the S′ phase is retarded by the electric field during the aging process. The electric field can influence the potential field of vacancies. As a result, the vacancies tend to move toward the opposite direction of the electric field.
Key words: 2E12 aluminum alloy; electric field; aging; mechanical properties; microstructure
