Titanium Powders via Gas-Solid Direct Reaction Process and Mechanical Properties of Their Extruded Materials

Abstract

In the present study, titanium (Ti) powders containing some nitrogen (N) atoms were prepared by a gas (N 2 )-solid (Ti starting powder) direct reaction process, and consolidated as an extruded rod with high strength and ductility at ambient temperature. Nitrogen content of the Ti powders via the gas-solid direct reaction process dramatically increased as the treatment time increased while no change in the oxygen content. Ti 2 N layers were formed at Ti powder surfaces via the above gas-solid reaction, however, no formation of Ti 2 N compounds was found in the extruded Ti materials. That is, the solid solution of N atoms in ¡-Ti was complete, and expected to enhance the mechanical strength of Ti materials. 0.2% yield strength (YS) and ultimate tensile strength (UTS) of wrought Ti-N materials were proportional to the additive nitrogen content, and the decrease of elongation was very limited. For example, the extruded Ti powder material with nitrogen content of 0.74 mass% revealed 974 MPa in 0.2%YS, 1120 MPa in UTS and 21.7% in elongation. These tensile properties were superior to those of the conventional Ti6Al-4V alloy with the standard specification of ASTM B348-00-GR5 (0.2%YS: 918 MPa, UTS: 1047 MPa, elongation: 16.6%).

Self-assembled, aligned TiC nanoplatelet-reinforced titanium composites with outstanding compressive properties

“…Contribution from the locally aligned TiC nanoplatelets thus accounts for >60%. The predominant strengthening effect of TiC reinforcements in Ti MMCs has been justified in other studies too [9,39]. However, the locally aligned TiC nanoplatelets resulted in both outstanding strength and ductility under compression.…”

Strengthening Effect of N-addition on Ti-Si-N Ternary Alloys Fabricated by Spark Plasma Sintering

“…Moreover, there are some abnormal areas observed in grain boundary of Ti-0.35Si-1TiN specimens under this area. This is caused from high N content dissolved in this area more than another area [6].…”

“…Silicon (Si) and Nitrogen (N) are biocompatibility element which can strengthen to Ti alloys [4,6] by difference solid solution mechanism. Si can strengthen Ti alloys by substitutional solid solution mechanism but N can strengthen Ti alloys by interstitial solid solution mechanism.…”

Evaluation of Fatigue Properties under Four-point Bending and Fatigue Crack Propagation in Austenitic Stainless Steel with a Bimodal Harmonic Structure

“…Grain refinement through severe plastic deformation is particularly effective in strengthening metallic materials; however, it leads to a decrease in ductility [9,11,12]. In order to suppress the decrease in ductility due to the formation of a homogeneous fine-grained structure, new microstructural designs were proposed [11][12][13][14][15][16][17]. Our research group has designed a harmonic structure using powder metallurgy to sinter mechanically milled stainless steel powders [18][19][20][21][22][23], which improve both their strength and ductility by suppressing necking during tensile deformation [20].…”