Effect of TiO2 particle size on microstructure and refining effect of Al-TiO2-C refiner
Huan LIU1, Rui-ying ZHANG1,2,*(), Jin-xuan LI1, Sen YANG1, Han YAN1
1 School of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot 010051, China 2 Inner Mongolia Key Laboratory of Light Metal Materials, Inner Mongolia University of Technology, Hohhot 010051, China
The Al-TiO2-C refiners were prepared by the in-situ exothermic dispersion method using Al, TiO2 and C powders. The particle sizes of TiO2 were 30, 60, 90 nm and 200 nm, respectively. The effects of particle size of TiO2 on the refiner microstructure were studied. The refinement effect on industrial pure aluminum was evaluated. The XRD, SEM and EDS techniques were used to characterize the phase composition and the microstructure of Al-TiO2-C refiners. The results show that the Al-TiO2-C refiners compose of Al3Ti, TiC and Al2O3.The particle size of TiO2 directly affects the amount, distribution and morphology of the second phase. When the particle size of TiO2 is 30-90 nm, the amount of Al3Ti and TiC is large. However, the segregation phenomenon is obviously observed. The distribution of particles is not uniform. The Al3Ti is lath-like. When the particle size of TiO2 is 200 nm, the distribution of second phases is uniform and the amount is small. The Al3Ti is blocky. After adding the Al-TiO2-C refiner prepared by 30 nm TiO2, the nucleation temperature of α-Al increases from 659.4 ℃ to 661.8 ℃.Re-heating temperature is dropped from 1.2 ℃ to 0.3 ℃.The minimum average grain size is 633 μm. The refinement effect is the best in this condition.
WANG P , ZHANG R Y , HAN X W , et al. Effect of Al-TiO2-C refiners prepared by different compacting pressures on refinement performance of ZL101 alloy[J]. Journal of Materials Engineering, 2018, 46 (8): 84- 90.
HUANG Y C , DU Z Y , XIAO Z B , et al. Effect of Al-Ti-C and Al-Ti-B on microstructure and mechanical performance of 7050 aluminum alloy[J]. Journal of Materials Engineering, 2015, 43 (12): 75- 80.
BIROL Y . Grain refining efficiency of Al-Ti-C alloys[J]. Journal of Alloys and Compounds, 2006, 422 (1): 128- 131.
ZHAO B Y , CAI Q Z , LI X W , et al. Effect of TiC nano particles supported by Ti powders on the solidification behavior and microstructure of pure aluminum[J]. Metals and Materials International, 2018, 24 (5): 945- 954.
ZHANG R Y , SHI Z M , LI H X . Effect of carbon on microstructure of TiC-Al2O3p/Al composites prepared by contact reaction technique[J]. Transactions of Materials and Heat Treatment, 2009, 30 (5): 30- 34.
SETOUDEH N , WELHAM N J . Effect of carbon on mechanically induced self-sustaining reactions (MSR) in TiO2-Al-C mixtures[J]. Journal of Refractory Metals and Hard Materials, 2016, 54, 210- 215.
ELMAHALLAWI I , ABDELKADER H , YOUSEF L , et al. Influence of Al2O3 nano-dispersions on microstructure features and mechanical properties of cast and T6 heat-treated Al-Si hypoeutectic alloys[J]. Materials Science and Engineering:A, 2012, 556, 76- 87.
CHAO Z L , ZHANG L C , JIANG L T , et al. Design, microstructure and high temperature properties of in-situ Al3Ti and nano-Al2O3 reinforced 2024Al matrix composites from Al-TiO2 system[J]. Journal of Alloys and Compounds, 2019, 775, 290- 297.
ZHU H G , JIANG Y L , YAO Q Q , et al. Reaction pathways, activation energies and mechanical properties of hybrid composites synthesized in-situ from Al-TiO2-C powder mixtures[J]. Materials Chemistry and Physics, 2012, 137 (2): 532- 542.
LIANG Y H , SHI Z M , LI G W , et al. Effects of Er addition on the crystallization characteristic and microstructure of Al-2wt%Fe cast alloy[J]. Journal of Alloys and Compounds, 2019, 781, 235- 244.
FARAHANY S , OURDJINI A , IDRSI M H , et al. Evaluation of the effect of Bi, Sb, Sr and cooling condition on eutectic phases in an Al-Si-Cu alloy(ADC12) by in situ thermal analysis[J]. Thermochimica Acta, 2013, 559, 59- 68.
BIROL Y . Efficiency of binary and ternary alloys from Al-Ti-B system in grain refining aluminum foundry alloys[J]. International Journal of Cast Metals Research, 2013, 26 (5): 283- 288.
BIROL Y . Design of potent grain refiners for wrought aluminum alloys[J]. International Journal of Cast Metals Research, 2013, 26 (5): 273- 278.
DONG X X , ZHANG Y J , JI S X . Enhancement of mechanical properties in high silicon gravity cast AlSi9Mg alloy refined by Al3Ti3B master alloy[J]. Materials Science and Engineering:A, 2017, 700, 291- 300.