Heterogeneous nucleation of α-Al primary crystal on L1_2 modified Al_(2.7)Ni_(0.3)Ti phase

摘要

The heterogeneous nucleation of alpha-Al primary crystal on the L1(2) modified A(l2.7)Ni(0.3)Ti (Al67Ni8Ti25) phase was investigated. To study the effectiveness of heterogeneous nucleation by the L1(2) modified Al(2.7)Ni(0.)3Ti phase, an Al-10 vol% Al2.7Ni0.3Ti refiner was fabricated by spark plasma sintering (SPS). It was found that the maximum grain refinement performance can be achieved by the Al-10 vol% Al2.7Ni0.3Ti refiner after a holding time of 690 s. The mechanical properties of pure Al casts were improved by using the Al-10 vol% Al2.7Ni0.3Ti refiner through grain refinement. However, the grain refinement performance is relatively weaker than expected. This is because the Al-10 vol% Al2.7Ni0.3Ti refiner does not have a high thermal stability. (c) 2018 The Japan Society of Applied Physics