摘要：Al-Ti-B中间合金用作铝和铝合金的细化剂，而铸态的细化效果有限。本文研究了等通道挤压(ECAP)对Al-Ti-B中间合金显微组织、显微硬度、电导率的影响以及不同ECAP变形Al-Ti-B中间合金对纯铝的细化效果。实验结果表明：经过不同道次ECAP变形的Al-Ti-B中间合金，显微组织明显发生变化，随道次的增加，杆状的组织逐渐变为细小的等轴晶。Al-Ti-B中间合金电导率随道次增加，从62.2%降低到56.9%。显微硬度随道次增加而逐渐增大，8道次硬度最大为61.8HV。
从经过ECAP变形Al-Ti-B细化的铝宏观照片可以看出，ECAP变形后的中间合金细化铝的效果比铸态中间合金细化的效果要好，随着ECAP道次的增加，柱状晶逐渐减少，细小的等轴晶组织逐渐增加，8道次等轴晶几乎布满整个截面，即8道次的Al-Ti-B中间合金细化铝的效果最好。中间合金细化铝的电导率随ECAP道次增加从66.9%降低到63.8%。细化铝的硬度随道次增加先增大后降低但趋于稳定，4道次中间合金细化的铝的硬度达到最大为38.72HV，8道次中间合金细化的铝硬度下降到38.62HV。
关键词：中间合金，Al-Ti-B，ECAP，细化剂，显微组织，显微硬度，电导率，细化效果
Abstract:Al-Ti-B master alloys is refiner for aluminum and aluminum alloy, but the refinement effect of the cast is limited. This article describes equal channel angular pressing(ECAP) on the Al-Ti-B master alloy microstructure, microhardness, electrical conductivity and the different passes ECAP， the Al-Ti-B master alloy of aluminum refinement effect. The results showed: after different passes of the Al-Ti-B master alloys significantly change the microstructure, with the increase passes，in which the organization was small equiaxed grains. Al-Ti-B master alloy electrical conductivity increases with the passes down to 56.9% from 62.2%, the hardness increases with the passes, the maximum hardness is 61.8HV,8 pass.
Can be seen from the aluminum macro photos, the effect of the master alloy after ECAP, refining aluminum is better than the effect of refinement of the cast master alloy, with the increasing of ECAP passes, columnarcrystal gradually decreased ,small equiaxed gradually increases, 8 pass inferior axis crystal is almost covered the entire cross-section, refinement effect of 8 pass Al-Ti-B master alloy was the best . The electrical conductivity of refinement aluminum down to 63.8% from 66.9% with the ECAP passes increasing，the hardness first increases with the pass and then decreased but steadily, the hardness of 4 pass master alloy refining aluminum maximum to 38.72HV. Aluminum hardness of 8 pass master alloys refined down to 38.62HV.
Keywords: master alloy, Al-Ti-B, ECAP, Refiner, microstructure, microhardness, electrical conductivity, refinement effect
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