(1. 邵陽(yáng)學(xué)院 機(jī)械與能源工程系，邵陽(yáng) 422004；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 研究了不同變形特性的Al-Cu合金相在等通道擠壓(ECAP)和多向壓縮(MAC)強(qiáng)塑性變形中的溶解行為。結(jié)果表明：可變形粒子θ′′和θ′在強(qiáng)變形中由于自身的應(yīng)變，產(chǎn)生了具有高能量的亞晶界和剪切變形帶，導(dǎo)致溶解發(fā)生，且由于表面能的作用使溶解持續(xù)進(jìn)行；而對(duì)于難變形的θ粒子而言，只有破碎后的尖銳菱角部分由于表面能的作用而發(fā)生溶解；相對(duì)純剪切應(yīng)力的ECAP方法，MAC方法由于壓應(yīng)力分量的作用能夠在析出相內(nèi)部更有效地引入應(yīng)變能，從而加速其溶解。
關(guān)鍵字: Al-Cu合金；等通道擠壓；多向壓縮；溶解行為；應(yīng)變能；表面能
（1. Department of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422004, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract: Based on equal-channel angular pressing (ECAP) and multi-axial compression (MAC), the dissolution behavior of second phases in Al-Cu binary alloy during severe plastic deformation was investigated. The results show that, for deformable particles, such as θ′′ and θ′, the dissolution occurs at subboundary and shear band creates due to particle deformation where Gibbs energy is quite high. The dissolution propagates due to the role surface energy. As for undeformed particles (θ) only those sharp corner and edge dissolve due to increasing the surface energy. Compared with ECAP, because of pure shear stress, the strain energy can be introduced into the precipitates more effectively due to compressive stress, the deformable particles thus dissolve more rapidly during MAC severe plastic deformation.
Key words: Al-Cu alloy; equal-channel angular pressing (ECAP); multi-axial compressions (MAC); dissolution behavior; strain energy; surface energy
