铝-钛-硼中间合金在等径角挤压过程中的变形行为

Deformation Behavior of Al-Ti-B Master Alloy during ECAP Process

采用等径角挤压(ECAP)技术对铝-钛-硼中间合金进行了室温挤压试验,用高温光学显微镜、扫描电镜、硬度计等分析了ECAP对合金中第二相粒子分布形态、尺寸及显微硬度的影响。结果表明:ECAP能显著改善合金中第二相粒子的分布形态,细化其尺寸;用试样绕其纵轴旋转90°、方向不变的加工路径(Bc),经过8道次挤压后,第二相粒子由原来的散乱分布变成较为均匀分布,由原长约20μm、宽约10μm的块状粒子细化为5μm左右的小颗粒;挤压1道次后,材料硬度增加最为明显,4道次后硬度增加趋势变缓。

Equal channel angular pressing （ECAP）was carried out on Al-Ti-B master alloy at room temperature. The effects of ECAP on distribution and grain size of the second-phase particles were analyzed with high temperature microscope and scanning electron microscope and the hardness of the material was measured by sclerometer after different ECAP passes. The results showed that the distribution of the second-phase particles was improved greatly and the grain size was remarkably refined by ECAP process. After 8 passes of ECAP in route Bc with the billet being rotated 90°clockwise, the second-phase particles were uniformly distributed in irA1 matrix and initial block-like particles with about 20 μm in length, 10 μm in diameter turned to be granular with an average grain size of about 5μm. After 1 pass, the hardness of the material increased significantly and the increasing trend became slower after 4 passes.