The sintering densification and microstructure evolutions of Ti-1Al-8V-5Fe alloy with Si additions

The cost-efficient Ti-1Al-8V-5Fe-xSi (denoted Ti-185-xSi hereafter, x = 0, 0.15, 0.3, 0.45, 0.6, 0.75) alloys are synthesized by cold compaction and sintering powder metallurgy (PM) technology using TiH2 and high-pure FeV80 powders. The sintering densification, microstructural evolutions and mechanical behavior of Ti-185-xSi alloys sintered at 1350 degrees C are investigated. The results show that the Si element is favorable to enhance the sintered density of Ti-185 alloys, which should be limited to 0.3%. The amount and average size of precipitate Ti5Si3 increase in the Ti-185 alloys with increasing Si content. Meanwhile, the Rockwell hardness of Ti-185 alloy also displays an increasing tendency, suggesting the Si element can improve the hardness of Ti-185. The Ti-185-0.15Si alloy possesses a better comprehensive mechanical property of strength (937 +/- 8 MPa) and elongation (3.5%). The high-performance Ti-185 alloy is successfully prepared using low-cost FeV80 master alloy with slight Si impurity instead of costly V.