Investigation of microstructure, crystallographic texture, and mechanical behavior of magnesium-based nanocomposite fabricated via multi-pass FSP for biomedical applications

Oxygen enhances the strength of titanium alloys in general; however, excess oxygen can make titanium alloys brittle. On the other hand, oxygen enhances the precipitation of the α phase and suppresses the formation of the ω phase. Thus, using the optimal amount of oxygen is important to improve the mechanical properties of titanium alloys. The role of oxygen in titanium alloys is still not well understood. The effect of oxygen on the mechanical behavior of a β-type titanium alloy, Ti-29Nb-13Ta-4.6Zr (referred to as TNTZ), which is used for biomedical applications, was investigated in this study. Oxygen was found to stabilize the ω phase in TNTZ. This behavior of oxygen is unusual considering the known behavior of oxygen in titanium alloys: oxygen is known to suppress the formation of the ω phase in titanium alloys. A small amount of oxygen increases the tensile strength but decreases the ductility of TNTZ. On the other hand, a large amount of oxygen, of around 0.7 mass%, increases both the tensile strength and the ductility of TNTZ. This phenomenon is unexpected.

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Influence of grain size and crystallographic texture on mechanical behavior of TIMETAL-LCB in metastable β-condition

Materials Science and Engineering A ◽

10.1016/j.msea.2012.09.024 ◽

2013 ◽

Vol 559 ◽

pp. 782-789 ◽

Cited By ~ 11

Author(s):

P.E. Markovsky ◽

Yu.V. Matviychuk ◽

V.I. Bondarchuk

Keyword(s):

Grain Size ◽

Mechanical Behavior ◽

Crystallographic Texture

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Microstructure, Mechanical Behavior and Crystallographic Texture in a Hot Forged Dual Phase Stainless Steel.

10.21203/rs.3.rs-295369/v1 ◽

2021 ◽

Author(s):

Riad Badji ◽

Bellel Cheniti ◽

Charlie Kahloun ◽

Thierry Chauveau ◽

Mohammed Hadji ◽

...

Keyword(s):

Stainless Steel ◽

Mechanical Behavior ◽

Grain Boundaries ◽

Crystallographic Texture ◽

Hot Forging ◽

Dislocation Nucleation ◽

S Phase ◽

Dual Phase ◽

Gradual Change ◽

Temperature Range

Abstract In this work, the hot forging behavior of a dual phase stainless steel in the temperature range of 850 – 1250 °C was investigated. The study revealed the occurrence of a significant cracking phenomenon for processing temperatures below 950 °C that was attributed to the combined effect of intermetallic precipitation and severe deformation. EBSD examination highlighted the occurrence of continuous dynamic recrystallization in both ferrite and austenite microstructures for processing temperatures above 1050 °C. Increasing the hot forging temperature to 1250 °C increased the low angle grain boundaries fraction and lowered the one of the high angle grain boundaries. This was accompanied by a gradual change in the crystallographic texture of the material. The mechanical behavior investigation showed that the steel plasticity, sharply dropped after forging at 850°, was gradually recovered after hot forging at temperatures above 1050°C. This was confirmed by nanoindentation measurements that revealed a remarkable increase of the hardness and young modulus of the steel after hot forging at 850°C and 950°C due to the dislocation nucleation and the s phase precipitation at g/δ interface. The enhancement of dislocation movement at the vicinity of the grain boundaries due to the absence of s phase as well as the dynamic recovery and recrystallization occurring in the temperature range of 1050°C - 1250 °C improved the global mechanical properties of the hot forged steel.

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