回复态Al-1.5%Mg单相合金大变形组织与强化机制

发布时间：2018-01-15 11:34

本文关键词：回复态Al-1.5%Mg单相合金大变形组织与强化机制　出处：《稀有金属》2017年03期 　论文类型：期刊论文

【摘要】：通过X射线衍射分析(XRD)、电子背散射衍射分析(EBSD)分析技术表征大应变后材料内部微观结构,并结合拉伸实验通过公式定量计算出各部分强化因素对合金屈服强度的贡献,研究了锻造及退火态铝镁单相合金(Al~(-1).5%Mg)在大变形过程中的组织演变及强化机制。结果表明:由于固溶镁元素的存在,铝镁单相合金在大变形过程能有效累积位错。等通道转角大应变加工使得平均晶粒尺寸减小(4.605μm降低至2.183μm),平均晶界角度提高(4.43°提高至6.51°),低角度晶界比例减少(0.97降低至0.89),晶体取向显著降低。后续的压缩大应变加工进一步降低平均晶粒尺寸(2.183μm降低至1.328μm),提高高角度晶界的比例(0.10提高至0.16)。大应变铝镁合金的强化主要由晶格摩擦应力、位错强化、低角度晶界强化、高角度晶界强化和固溶强化组成,其中位错强化和低角度晶界强化贡献占绝大部分。
[Abstract]:The microstructure of the material was characterized by X-ray diffraction (XRD) and electron backscatter diffraction (EBSD). The contribution of each part of the strengthening factors to the yield strength of the alloy was calculated quantitatively by the formula combined with the tensile test. The microstructure evolution and strengthening mechanism of forging and annealed Al-Mg single phase alloy (Al _ (1) O _ (-1) 路5 mg) during large deformation are studied. The results show that the existence of solid solution magnesium is the main reason. The single phase aluminum-magnesium alloy can effectively accumulate dislocations during large deformation. The average grain size decreases by 4.605 渭 m to 2.183 渭 m after processing with high strain at equal channel angle. The average grain boundary angle increased from 4.43 掳to 6.51 掳and the ratio of low angle grain boundary decreased from 0.97 to 0.89). The crystal orientation was significantly decreased, and the average grain size was further reduced to 1.328 渭 m by further compression and high strain processing (2.183 渭 m). The ratio of high angle grain boundary is increased from 0.10 to 0.160.The strengthening of large strain aluminum magnesium alloy is mainly caused by lattice friction stress, dislocation strengthening and low angle grain boundary strengthening. The composition of high angle grain boundary strengthening and solid solution strengthening is composed of dislocation strengthening and low angle grain boundary strengthening.
【作者单位】：江苏大学先进制造与现代装备技术工程研究院;
【基金】：国家自然科学基金项目(51074079) 江苏大学研究生科研创新计划项目(KYXX_0031)资助
【分类号】：TG146.21
【正文快照】： 等通道转角挤压(ECAP,equal channel angularpressing)是一种采用纯剪切方式来减小材料晶粒尺寸及调控晶体取向的剧烈塑性变形法[1-3]。它可以使材料内部应变大量积累,使材料晶粒得到大幅细化,因而广受关注。但在工业应用上,由于其受压力及模具的限制,加工获得的工件尺寸并不

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