Synthesis of TiAl-Al2O3 composites by high energy milling and hot-press sintering
(1.陕西省咸阳市陕西科技大学材料科学与工程学院
2.陕西省西安市西安交通大学材料力学行为的影响国家重点实验室
3.State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
4.School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xianyang 712081, China)
2.陕西省西安市西安交通大学材料力学行为的影响国家重点实验室
3.State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
4.School of Materials Science and Engineering, Shaanxi University of Science and Technology, Xianyang 712081, China)
Abstract: A sub-microstructure titanium aluminide alloy /Al2O3 (3A) composite was obtained by crystallization of the amorphous powders, which were prepared by mechanical alloying (MA) in a planetary ball milling system using Ti-Al-TiO2 as raw materials. The experimental results show that, when the milling time increases up to 30 h, the hcp Ti(Al) supersaturated solid solution disappears, only amorphous phase is left. The compact samples were synthesized by hot-press to 1 200 ℃ with the amorphous as a precursor; the final phases of the matrix and strengthened phase are γ-TiAl and Al2O3. The phases come from in situ crystallization and transformation. The samples, fabricated from the amorphous phase by hot press sintering, have high bending strength and fracture toughness.
Key words: titanium aluminide intermetallics; Al2O3; composite; mechanical alloying; crystallization