(中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用力學(xué)性能試驗(yàn)機(jī)、透射電子顯微鏡(TEM)、應(yīng)力時(shí)效爐等手段研究時(shí)效拉應(yīng)力對(duì)2E12鋁合金的力學(xué)性能和微觀組織的影響，并分析應(yīng)力對(duì)2E12鋁合金的作用機(jī)理。結(jié)果表明：外加應(yīng)力能提高2E12鋁合金的強(qiáng)度，增大合金各向異性的差異；外加應(yīng)力能促進(jìn)S相的析出，并產(chǎn)生明顯的應(yīng)力位向效應(yīng)；應(yīng)力時(shí)效能使2E12鋁合金的無(wú)沉淀析出帶變窄，阻止晶界沉淀相的連續(xù)析出；應(yīng)力時(shí)效為控制高強(qiáng)鋁合金的各向異性提供了一種新方法。
關(guān)鍵字: 2E12鋁合金；應(yīng)力時(shí)效；力學(xué)性能；應(yīng)力位向效應(yīng)；無(wú)沉淀析出帶
microstructures of 2E12 aluminum alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The influences of tensile stress aging on the mechanical properties and microstructure of 2E12 aluminum alloy were investigated by means of mechanical tests, transmission electronic microscopy (TEM) and stress aging furnace. The effect mechanic of tensile stress on 2E12 aluminum alloy was analyzed. The results show that the external stress during aging improves the ultimate strength and increases the ultimate strength anisotropy of 2E12 aluminum alloy. The external stress can enhance the precipitation of S phase and induce the preferred orientation of precipitated S phase. Under the external stress aging, the precipitation free zone (PFZ) is narrowed and the distribution of those precipitates changes from chains to non-continuous ones. The stress aging provides a tool to control the anisotropy in high strength aluminum alloys.
Key words: 2E12 aluminum alloy; stress aging; mechanical properties; stress oriented effect; precipitation free zone
