access icon free Effect of compaction pressure on the densification, microstructure, and mechanical properties of Ti-1Al-8V-5Fe alloy based on TiH2 and HDH-Ti powders

The high-strength of Ti-1Al-8V-5Fe (Ti-185) alloy is due to TiH2 powders produced at different compaction pressures and compared with hydride–dehydride-Ti powders. The objective of this work was to investigate the microstructural evolution and mechanical properties of Ti-185 alloy under different compaction pressures. The dehydrogenation characteristics of TiH2-185 and the oxygen contents of sintered samples were evaluated by thermogravimetric analysis and mass spectrometer (TG-MS) and oxygen/nitrogen (O/N) analysers. The corresponding microstructural evolution and change in mechanical properties were analysed by means of scanning electron microscopy, X-ray diffraction, electro-universal tester, and hardness tester, respectively. Results show that with the increase in compaction pressure, the green and sintered density and densification rates increase, but the volume fraction of α-phase decreases. The TiH2-185 samples have higher densification and sintered density, lower oxygen content than Ti-185 samples, which is attributed to its better compressibility and superior self-cleaning ability as well as more water produced. In addition, the sintered TiH2-185 samples exhibit higher yield strength and hardness in comparison with the sintered Ti-185 samples. The enhanced mechanical properties are attributed to its higher density and less soft α-phase in the microstructure.

Inspec keywords: scanning electron microscopy; titanium compounds; sintering; compaction; crystal microstructure; compressibility; X-ray diffraction; hardness testing; hardness; vanadium alloys; powders; iron alloys; yield strength; titanium; titanium alloys; mass spectroscopic chemical analysis; aluminium alloys; densification

Other keywords: dehydrogenation characteristics; TG-MS; X-ray diffraction; sintered density; α-phase; TiAlVFe-TiH2; hardness tester; O/N analysers; volume fraction; compressibility; microstructural evolution; yield strength; scanning electron microscopy; mechanical properties; densification; self-cleaning ability; electro-universal tester; TiAlVFe-Ti; compaction pressure

Subjects: Deformation, plasticity and creep; Fatigue, brittleness, fracture, and cracks; Microstructure; Nondestructive materials testing methods; Fatigue, embrittlement, and fracture; Solubility, segregation, and mixing; Powder techniques, compaction and sintering; Mass spectrometry (chemical analysis); Deformation and plasticity

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