The Range of the Occurrence of α Phase in near β Titanium Alloys

2016 ◽  
Vol 682 ◽  
pp. 77-82
Author(s):  
Janusz Krawczyk ◽  
Łukasz Frocisz ◽  
Robert Dąbrowski ◽  
Edyta Rożniata ◽  
Tomasz Śleboda
Keyword(s):  
Heat Treatment ◽  
Titanium Alloys ◽  
Processing Time ◽  
Casting Process ◽  
Compression Tests ◽  
Phase Precipitation ◽  
Phase Dissolution ◽  
Β Phase ◽  
Α Phase ◽  
Temperature Strain

Two near β titanium alloys (Ti-3Al-8V-6Cr-4Mo-4Zr and Ti-10V-2Fe-3Al) were investigated in his research. Both materials contained disperse precipitations of α phase in β phase matrix. In the case of Ti-3Al-8V-6Cr-4Mo-4Zr alloy clear segregation of alloy constituents, resulting from casting process, were observed. This segregation caused different susceptibility to α phase precipitation in dendritic and interdendritic areas in the microstructure of the investigated alloy. The influence of the temperature, strain and processing time on α phase dissolution was determined. Gleeble compression tests were performed on both of the investigated alloys. The research showed different character of the influence of strain rate and processing time on the temperature of α phase dissolution for each alloy. The effect of heat treatment on α phase dissolution during ageing of the investigated alloys was also determined. The possibility of obtaining homogenous microstructure in these alloys by properly designed heat treatment was also discussed.

scholarly journals Modeling of the effect of the β phase deformation on the α phase precipitation in near-β titanium alloys

2006 ◽  
Vol 54 (16) ◽  
pp. 4261-4271 ◽  
Author(s):  
Julien Da Costa Teixeira ◽  
Benoît Appolaire ◽  
Elisabeth Aeby-Gautier ◽  
Sabine Denis ◽  
Fabien Bruneseaux
Keyword(s):  
Titanium Alloys ◽  
Phase Precipitation ◽  
Β Phase ◽  
Α Phase ◽  
Phase Deformation

The Effect of Tin and Heat Treatment in Brass on Microstructure and Mechanical Properties for Solving the Cracking of Nut and Bolt

2013 ◽  
Vol 389 ◽  
pp. 237-244
Author(s):  
Wichan Chuaiphan ◽  
Loeshpahn Srijaroenpramong ◽  
Dumrongrit Pinpradub
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Precipitation Hardening ◽  
Casting Process ◽  
Commercial Grade ◽  
Β Phase ◽  
Α Phase ◽  
Microstructure And Mechanical Properties ◽  
Sand Mould ◽  
Brass Sample

This work studied the effect of tin (1%Sn) addition in brass 60%Cu+40%Zn (commercial grade) by casting process conducted poured melt metals inside a sand mould and heat treatment in cast brass on microstructure and mechanical properties for solving the cracking of nut and bolt. Three conditions of brass sample for experiment viz.- brass 60%Cu + 40%Zn (commercial grade), brass 60%Cu + 39%Zn+1%Sn (as-cast) and brass 60%Cu+39% Zn+1%Sn (precipitation hardening). The microstructure of specimens all condition, it was found that consists of α phase and β phase. Which brass addition 1% Sn, the β phase content in α phase matrix structure more than brass commercial grade. For microstructure of brass produce by precipitation hardening, shape of α phase are slender and long which have slight distributed in β-phase. The mechanicals properties, that is hardness, ultimate tensile strength and compressive strength. It was found that the brass 60%Cu+39% Zn+1%Sn (precipitation hardening), all test mechanical properties it was higher than the all samples condition. This results can be explain incharacterization of microstructure to gives deformation of copper alloy.

Influence of Phases Stability on the Hydrogen Diffusion Coefficient in Ti-6Al-4V

2020 ◽  
Vol 986 ◽  
pp. 33-40
Author(s):  
Mohammed Kasim Mohsun
Keyword(s):  
Heat Treatment ◽  
Diffusion Coefficient ◽  
Titanium Alloys ◽  
Hydrogen Diffusion ◽  
Volume Fraction ◽  
Substantial Effect ◽  
Diffusion Annealing ◽  
Hydrogen Treatment ◽  
Β Phase ◽  
Hydrogen Diffusion Coefficient

For a unique microstructure creation, thermo-hydrogen treatment (THT), using hydrogen as a temporary alloying element within the heat treatment, is applied. This advanced heat treatment requires reliable data about the hydrogen diffusion coefficient (DH) for understanding diffusion kinetics and its effect on the mechanical behavior of the resulted phases. In this research, three different homogeneous microstructures were established for the investigation using different homogenization parameters. After that, the concentration of hydrogen, charged in the half-length of thin titanium rods via electrochemical hydrogenation, is specified. Then, a diffusion annealing heat treatment was carried out at different temperatures, leading to hydrogen diffusion in the hydrogenated specimens. Furthermore, DH was systematically determined using two methods including the explicit finite difference method (EFDM) and Matano technique (MT). For this purpose, Abaqus software was employed for modeling the hydrogen gradient established in the specimens. Additionally, scanning electron microscopy (SEM) was used for the microstructure examination in order to specify the influence of different hydrogen concentrations on the hydrogenated specimens. The experimental outcomes reveal a substantial effect of the β phase stability and grains sizes of the β and α phases on the hydrogen diffusion. Correspondingly, the results confirm that DH was independent of the hydrogen concentration, and obeys an Arrhenius-type temperature dependence. Furthermore, hydrogen diffusion in the α+β titanium alloys Ti-6Al-4V was slower in comparison to the hydrogen diffusion in the metastable β titanium alloys Ti-10V-2Fe-3Al. In conclusion, it was observed that DH is influenced by the previously performed heat treatments that determine the resulted microstructure types, and a slight influence of the volume fraction of the α phase on DH was observed as well.

scholarly journals Eliminating continuous grain boundary α phase in laser melting deposited near β titanium alloys by heat treatment

2019 ◽  
Vol 563 ◽  
pp. 022025
Author(s):  
Penglin Li ◽  
Changmeng Liu ◽  
Jie Wang ◽  
Jiping Lu ◽  
Shuyuan Ma ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Titanium Alloys ◽  
Laser Melting ◽  
Α Phase

Effect of Heat Treatment on the Damage Tolerance Properties of Ti-6Al-2Zr-2V-1.5Mo ELI Alloy Plate

2011 ◽  
Vol 690 ◽  
pp. 282-285
Author(s):  
Xiao Xiang Wang ◽  
Song Xiao Hui
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Fatigue Crack ◽  
Annealing Temperature ◽  
Damage Tolerance ◽  
Phase Zone ◽  
Alloy Plate ◽  
Β Phase ◽  
Α Phase ◽  
Treatment Conditions

Effect of heat treatment on the damage tolerance properties of a newly developed middle strength high damage tolerance Ti-6Al-2Zr-2V-1.5Mo ELI alloy plate has been investigated in this paper by testing fracture toughness and fatigue crack-extending rate of the plate under three heat treatment conditions and fractograph inspection of the samples. It has been found that with the increasing of the primary annealing temperature from 900°C to 950°C, the fracture toughness increased and the fatigue crack extending rate decreased significantly. Microstructural observation has found that the crack expanded through the α beaming and mainly are perpendicular to the α orientation in the lamellar structure which annealed in α+β phase zone. For the Widmanstaten structure, which can be obtained from annealing in single β phase zone, the continuous grain boundary α phase and α beaming boundary hinder the crack expanding significantly.

Phase Constitution and Heat Treatment Behavior of Zr-Nb Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 1435-1440 ◽  
Author(s):  
Masahiko Ikeda ◽  
Tsuyoshi Miyazaki ◽  
Satoshi Doi ◽  
Michiharu Ogawa
Keyword(s):  
Heat Treatment ◽  
Elastic Modulus ◽  
Elastic Moduli ◽  
X Ray Diffraction ◽  
Phase Constitution ◽  
X Ray ◽  
Β Phase ◽  
Ω Phase ◽  
Solution Treated ◽  
Α Phase

Phase constitution in the solution-treated and quenched state and the heat treatment behavior were investigated by electrical resistivity, hardness, and elastic modulus measurements, X-ray diffraction, and optical microscopy. Hexagonal martensite and the β phase were identified in the Zr-5mass%Nb alloy. β and ω phases were identified in the Zr-10 and 15mass%Nb alloys, and only the β phase was identified in the Ti-20Nb alloy. Resistivity at RT, Vickers hardness and elastic modulus increased up to 10Nb and then decreased dramatically at 15Nb. Above 15Nb, these values slightly decreased. The elastic moduli for 15Nb and 20Nb were 59.5 and 55.5 GPa, respectively. On isochronal heat treatment, the isothermal ω phase precipitated between 473 and 623 K and then the α phase precipitated in the 10Nb, 15Nb and 20Nb alloys.

Effect of Heat Treatments on the Bio-Corrosion Resistance of Magnesium Alloy Mg-8.0Al-1.0Zn-xGd

2011 ◽  
Vol 213 ◽  
pp. 497-501
Author(s):  
Lei Li ◽  
Rui He ◽  
Guo Jie Huang ◽  
Shui Sheng Xie
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Annealing Treatment ◽  
Microstructure Analysis ◽  
Β Phase ◽  
Α Phase ◽  
Treatment Procedures ◽  
Human Fluid

In order to improve the bio-corrosion resistance of magnesium alloy Mg-8.0Al-1.0Zn-xGd in the simulated human fluid, different heat treatment procedures were studied. Results showed that annealing treatment lowered the alloy’s corrosion resistance and hardness, while T6 treatment (solid solution+ aging) improved the alloy’s corrosion resistance and hardness. Microstructure analysis showed that the β phase dissolved into α phase after the annealing treatment. Hence, annealing treatment decreased the alloy’s corrosion resistance. However, lots of β-phases were precipitated in the T6 heat treatment, and they impeded the corrosion extending.

Effect of Heat Treatment on Microstructure and Mechanical Properties of Ti-13Nb-13Zr Alloy Produced by Powder Metallurgy

2014 ◽  
Vol 802 ◽  
pp. 457-461 ◽  
Author(s):  
José Hélio Duvaizem ◽  
N.M.F. Mendes ◽  
J.C.S. Casini ◽  
A.H. Bressiani ◽  
H. Takiishi
Keyword(s):  
Heat Treatment ◽  
Elastic Modulus ◽  
Powder Metallurgy ◽  
Phase Precipitation ◽  
X Ray Diffraction ◽  
Dynamic Mechanical Analyzer ◽  
X Ray ◽  
Α Phase ◽  
13Zr Alloy ◽  
Scanning Electron

Ti-13Nb-13Zr alloy produced via powder metallurgy was submitted to heat treatment under various conditions and the effects on microstructure and elastic modulus were investigated. Heat treatment was performed using temperatures above and below α/β transus combined with different cooling rates – furnace cooling and water quenching. Microstructure and phases were analyzed employing scanning electron microscopy and X-ray diffraction. Elastic Modulus was determined using a dynamic mechanical analyzer (DMA). The results indicated that α phase precipitation and elastic modulus values increased after heat treatment performed using temperature below α/β transus. However, when it was performed above α/β transus and using higher cooling rate, a decrease in elastic modulus was observed despite higher α phase precipitation, indicating that the microstructural modifications observed via SEM, due to the presence of martensitic α phase, influenced on elastic modulus values.

Influence of Heat Treatment on Microstructure and Tensile Property of Ti-5Al-5Mo-5V-3Cr-1Fe Alloy

2013 ◽  
Vol 365-366 ◽  
pp. 1003-1006
Author(s):  
Yan Yan Fu ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Xu Jun Mi
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Tensile Property ◽  
Aging Temperature ◽  
Aging Treatment ◽  
Minimum Level ◽  
Β Phase ◽  
Α Phase

The effect of solution and aging temperatures on microstructure and tensile property of Ti-5Al-5Mo-5V-3Cr-1Fe Alloy was investigated. The results showed that the tensile strength lowered, when the solution and aging temperature rose respectively. The alloy with different heat treatments showed better tensile strength totally, i.e. the minimum level of ultimate and yield strength passed 1280 MPa and 1245MPa. The highest ultimate tensile strength could reach 1445 MPa. After (α+β) solution and aging treatment, the microstructure consists of primary α phase and transformed β phase with fine secondary α phase precipitating to improve the tensile strength effectively.

scholarly journals Phase transformations during continuous heating: effect of Sn addition on the microstructure of Ti-13Mo alloy

2020 ◽  
Vol 321 ◽  
pp. 05017
Author(s):  
M.G. de Mello ◽  
F.H. da Costa ◽  
R. Caram
Keyword(s):  
Lattice Parameter ◽  
Continuous Heating ◽  
Phase Precipitation ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Β Phase ◽  
Ω Phase ◽  
Α Phase ◽  
Heat Treated ◽  
Kinetics Of

The addition of Sn to the Ti-Mo system can diminish the formation of ω phase and slow down the precipitation kinetics of α phase due to the low atomic diffusivity of Sn atoms in Ti. To explore α phase precipitation in Ti-13Mo and Ti-13Mo-6Sn (wt.%) alloys, differential scanning calorimetry (DSC) was applied using different heating rates to determine ω phase dissolution, α phase precipitation and β transus temperatures. The DSC results were then used to determine the aging heat treatment temperatures. Samples were heat-treated at 600 °C for 1 h and 24 h to examine microstructure features. The addition of Sn to Ti-13Mo alloy was found to increase the β phase lattice parameter, increasing β transus temperatures and resulting in microstructures with heterogeneous and coarser α phase precipitation.

Sign in / Sign up

Export Citation Format

Share Document