Showing 5 results for Ti-6al-4v
K. Farmanesh and A. Najafi-Zadeh,
Volume 23, Issue 1 (7-2004)
Abstract
Among the titanium alloys, Ti-6Al-4V is the most widely used. In the present work, the uniaxial hot compressive behavior of Ti-6Al-4V has been investigated under constant strain rates. A series of dilatometery experiments were carried out to determine the transformation temperatures at different cooling rates. Specimens were homogenized at 1050 °C for 10 minutes followed by fast cooling to different straining temperatures from 1050 to 850°C. The cooling rate was chosen fast enough to prevent high temperature transformation during cooling. A series of isothermal compression tests were conducted at different temperatures of 850, 900, 950, 1000, 1050°C at constant true strain rates of 0.1, 0.01 and 0.001 s-1, respectively. Samples were uniaxialy compressed to a true strain of 0.55 followed by water quenching to room temperature. The apparent activation energy for compression in two phase regions was calculated at 840 KJmol-1. The partial globularization of a-phase was observed in the specimens deformed at low strain rates and at temperatures near the transformation zone followed by annealing.
H. Omidvar, B. Fallah Ghanbary, M. Tamizifar,
Volume 30, Issue 2 (12-2011)
Abstract
In this paper, plastic flow behavior and micro structural evolution of Ti-6Al-4V alloy in temperature range of 750-1050 °C and strain rate range of 0.001-0.1 (S-1) in isotherm compression condition were investigated. The purpose was to estimate activation energy of globularization of lamellar structure and analyze this process kinetically. True Stress-strain curves obtained at the temperatures below 950 °C indicate a limited amount of flow softening imputed to a dynamic recrystallization occuring at about 950 ˚C. In contrast, at higher temperatures, the flow stress increases linearly with plastic strain until at temperatures about 1015°C where flow stress becomes nearly independent of the temperature. By analyzing flow stress data via Zener-Hol-lomon and sellars equation, Q activation energy of dynamic recrystallization was estimated and structural equation of plastic flow was obtained, whixh were comparable to results raeched by other investigators.
Reza Eshghi, S.m.hadavi, V.varmazyar,
Volume 33, Issue 3 (3-2015)
Abstract
In this research, Ti-6Al-4V alloy was brazed with 410 stainless steel by three different filler metals as silver-base,
nickel-base, and titanium-base alloys. In order to obtain optimum clearance, brazing was done in three different clearances
of 0.02, 0.04 and 0.06 mm. Also, the strength and hardness of the brazing zone were investigated. The results of shear strength
showed that the brazed samples with titanium-base alloy at the clearance of 0.02 mm had the maximum strength among the
different samples which was 149.5 MPa.
M.r. Garsivaz Jazi, M.a. Golozar , K. Raeissi,
Volume 33, Issue 3 (3-2015)
Abstract
In this study, the chemical composition, thickness and tribocorrosion behavior of oxide films prepared on Ti-6Al-4V alloy by anodising treatment in H2SO4/H3PO4 electrolyte at the potentials higher than the dielectric breakdown voltage were evaluated. The thickness measurement of the oxide layers showed a linear increase of thickness by increasing the anodizing voltage. The EDS analysis of oxide films demonstrated precipitation of sulfur and phosphor elements from electrolyte into the oxide layer. Tribocorrosion results indicated that the tribocorrosion behavior of samples was significantly improved by anodising
process. Furthermore, the tribocorrosin performance of thesamples anodised at higher voltages was enhanced. SEM and EDS of worn surfaces indicated that the oxide layer on the samples anodised at lower voltages was totally removed, but for the samples anodised at higher voltages, the oxide layer was only locally removed within the wear track. Moreover, measurement of wear volume of the treated samples exhibited lower values on the samples anodised at higher voltages.
G. R. Faghani, A. R. Khajeh-Amiri,
Volume 38, Issue 4 (1-2020)
Abstract
Due to special properties such as low density, high strength and high corrosion resistance Ti-6Al-4V alloy has been used extensively in various industries, especially in the aerospace aspects. However the major problem of this alloy is its poor tribological properties under relatively high loads. In the present study, in order to improve the tribological properties of mentioned alloy, chromium particles were added to Ti-6Al-4V layers in the nitrogen-containing atmosphere during the Tungsten Inert Gas (TIG) welding process. Microstructural investigations using optical microscopy, X-ray diffraction analysis and scanning electron microscopy, proved the formation of TiN, TiCr2 and Cr2N particles in the matrix of hard titanium phase. The hardness of TIG alloyed layer increased to 1000 HV0.3 which was 4 times higher than that of the base alloy. Moreover, the wear rate of TIG alloyed samples with chromium and nitrogen under 30N load and distance of 1000 m was 5.9 times lower than that of the bare Ti-6Al-4V alloy.
