Ti6Al4V alloy fabricated by gelcasting based on low-oxygen gel system using hydride-dehydride titanium alloy powders

2021 ◽  
Author(s):  
Yanru Shao ◽  
Fang Yang ◽  
Cunguang Chen ◽  
Yang Zhou ◽  
Xinbo He ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Ti6al4v Alloy ◽  
Low Oxygen ◽  
Gel System

scholarly journals Constitutive Model and Cutting Simulation of Titanium Alloy Ti6Al4V after Heat Treatment

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4145
Author(s):  
Xiaohua Qian ◽  
Xiongying Duan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
Orthogonal Cutting ◽  
Treatment Method ◽  
Dynamic Mechanical Properties ◽  
Ti6al4v Alloy ◽  
Stress Strain ◽  
Cutting Simulation ◽  
Titanium Alloy Ti6al4v

As a typical high specific strength and corrosion-resistant alloy, titanium alloy Ti6Al4V is widely used in the aviation, ocean, biomedical, sport, and other fields. The heat treatment method is often used to improve the material mechanical properties. To investigate the dynamic mechanical properties of titanium alloy Ti6Al4V after heat treatment, dynamic compressive experiments under high temperature and high strain rate were carried out using split Hopkinson press bar (SHPB) equipment. The stress–strain curves of Ti6Al4V alloy under different temperatures and strain rates were obtained through SHPB compressive tests. The Johnson–Cook (J–C) constitutive equation was used for expressing the stress–strain relationship of titanium alloy under large deformation. In addition, the material constants of the J–C model were fitted based on the experimental data. An orthogonal cutting simulation was performed to investigate the cutting of Ti6Al4V alloy under two different numerical calculation methods based on the established J–C model using the finite element method (FEM). The simulation results confirm that the adiabatic mode is more suitable to analyze the cutting of Ti6Al4V alloy.

Sustained Load Cracking of Titanium Alloy Weldments

2005 ◽  
Author(s):  
Tasos Kostrivas ◽  
Lee Smith ◽  
Mike Gittos
Keyword(s):  
Stress Intensity Factor ◽  
Titanium Alloy ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Postweld Heat Treatment ◽  
Alloy Sheet ◽  
Test Method ◽  
Sustained Load ◽  
Low Oxygen ◽  
Delayed Cracking

Failure of critical titanium parts, including some offshore components, has drawn attention to delayed cracking in Ti-6Al-4V alloys, but, given good design and alloy variant selection, such failures are avoidable. Delayed cracking, or sustained load cracking (SLC), can occur at low to moderate temperature (approximately: −50 to 200°C), depending on the titanium alloy and condition. Appropriate testing methods are required to generate stress intensity threshold values (KISLC) that can be incorporated into the design of titanium structures and recommendations are needed on the optimum chemistry and microstructure for greatest resistance. In the present work threshold stress intensity factor data (KISLC) were generated for Ti-6Al-4V alloy sheet, forgings, pipe and weldments using two different rising stress intensity factor test methods. It is concluded that material with a beta-annealed microstructure and low oxygen content (i.e. extra-low interstitial material such as ASTM Grades 23 and 29), has high resistance to SLC and that weld metal and transformed heat-affected zone also perform well, before and after postweld heat treatment, provided interstitial element pick-up during welding is prevented. Purchasing material in a general ‘mill annealed’ condition is not recommended without specifying acceptable microstructures. Further refinement of test method is also recommended for defining KISLC.

A Review on Surface Engineering of Ti6Al4V Titanium Alloy Using Gas and Laser Nitriding Techniques

2015 ◽  
Vol 766-767 ◽  
pp. 618-625 ◽  
Author(s):  
J.R Deepak
Keyword(s):  
Titanium Alloy ◽  
Surface Properties ◽  
Surface Engineering ◽  
Surface Hardness ◽  
Aircraft Engine ◽  
Ti6al4v Alloy ◽  
Surface Stability ◽  
Laser Nitriding ◽  
Gas Nitriding ◽  
Grade 5

Nitriding is the most common surface engineering technique that is being used in Titanium alloys for improving their surface properties, viz hardness, wear resistance, etc. Ti6Al4V (Grade 5) Titanium Alloy is a super alloy that exhibits excellent mechanical strength; it is highly resistance to creep at very high temperatures which maintains good surface stability. It is resistant to corrosion and oxidation. The main objective of this review paper is to study the recent research works carried on Nitriding of Ti6Al4V alloy by using, viz gas Nitriding and laser Nitriding. This process is used in the surface hardening of machine parts such as aircraft engine parts, crank pins, valve seats, gears, bush, aero engine cylinders, aero crank shafts. Gas Nitriding is a diffusional technique in which the nitrogen atoms are diffused into the surface of the metal to obtain hard surface. By Laser Nitriding is a diffusional technique by which the surface properties of the titanium alloy is enhanced. Laser nitriding process comprises of various stages, viz, transport of heat, melting effect, diffusion and convection effect. By Nitriding technique the surface hardness of super alloys like Titanium Alloy Ti6Al4V Grade 5 can be increased by increasing the hardness on the surface there by its scope of application is widened. In this paper a literature survey is carried out and the recent research works on surface engineering of Ti6Al4V alloy using gas and laser Nitriding technique is summarized.

THE TRIBOLOGICAL PROPERTIES OF THE Ti6Al4V ALLOY WITH NITROGEN ION IMPLANTATION

Tribologia ◽  
2019 ◽  
Vol 283 (1) ◽  
pp. 37-47
Author(s):  
Katarzyna PIOTROWSKA ◽  
Paweł BARANOWICZ ◽  
Joanna WYSOKIŃSKA-MISZCZUK ◽  
Monika MADEJ ◽  
Monika SKÓRA
Keyword(s):  
Titanium Alloy ◽  
Ion Implantation ◽  
Tribological Properties ◽  
Contact Angles ◽  
Ti6al4v Alloy ◽  
Surface Geometry ◽  
Tribological Tests ◽  
Ringer’S Solution ◽  
Nitrogen Ions ◽  
Titanium Alloy Ti6al4v

The article presents the analysis of the influence of ion implantation on the properties of titanium alloy used in biotribological systems. The object of the study was the titanium alloy Ti6Al4V implanted with nitrogen ions. Tribological model tests were carried out in combination with a sphere with Al2O3 – a Ti6Al4V alloy disc implanted with N+ ions. Experimental friction tests were carried out on pin-on-disc testers in conditions of technically dry conditions and in conditions of lubrication with the Ringer’s solution. The tests on the TRB tester were carried out in a swinging motion, while on the T-01 tester in a sliding movement. Friction coefficient and wear were determined for all tests. Surface morphology testing and chemical composition analyses were performed using the Jeol JSM-7100F scanning electron microscope, equipped with an EDS microanalyzer. Surface geometry measurements prior to and after tribological tests were performed on a Taylor Hobson’s Talysurf CCI contactless optical profilometer. The optical tensiometer was used to determine the contact angles with demineralized water and Ringer’s solution. The tribological tests of the titanium alloy Ti6Al4V lead to the conclusion that implantation of N+ ions results in better tribological properties of the alloy. The best tribological characteristics were obtained for a titanium alloy implanted with nitrogen ions under technically dry friction conditions. The influence of the tribological system on Ringer’s fluid influenced the reduction of coefficients of friction in the oscillating movement (Tribometer TRB) and sliding motion (Tester T-01M). In the case of a oscillating movement, higher wear of the tested friction pair was observed under friction conditions with the Ringer solution lubrication.

Research on Law and Mechanism of Hydrogen Induced Softening in Ti6Al4V Alloy in the Temperature Range 400 °C to 1010 °C

2015 ◽  
Vol 1120-1121 ◽  
pp. 1202-1207
Author(s):  
Shu Hui Huang ◽  
Ying Ying Zong ◽  
De Bin Shan
Keyword(s):  
Titanium Alloy ◽  
Phase Region ◽  
Ti6al4v Alloy ◽  
Temperature Range ◽  
Β Phase ◽  
Solution Strengthening ◽  
The Law ◽  
Alloy Softening ◽  
The Relationship ◽  
Phase Solution

The law and mechanism of hydrogen induced softening in Ti6Al4V alloy in the temperature range 400 °C to 1010 °C are researched by lots of isothermal hot compression experiment in this paper. The relationship between σh (the true stress when the test is compressed to half of its original height) and CH (hydrogen content) is investigated to describe the law. The results show that, Between 400 °C and 450 °C, the plasticity increases at first, and then decreases and the strength is almost changeless with the CH rising. Between 480 °C and 950 °C, the strength decreases at first, and then increases with the CH rising. In α+β phase region, the strength decreases with the CH rising. In β phase region, the strength increases with the CH rising. Hydrogenation induced α phase high temperature softening and hydrogenation promoting α→β phase transition are the main reasons for hydrogen induced titanium alloy softening. Hydrogenation induced β phase solution strengthening is the reason for hydrogen induced titanium alloy strengthening. And the relationship between furnace temperature and vacuum is investigated during dehydrogenation heat treatment.

scholarly journals Corrosion Resistance and Surface Bioactivity of Ti6Al4V Alloy after Finish Turning under Ecological Cutting Conditions

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6917
Author(s):  
Kamil Leksycki ◽  
Agnieszka Kaczmarek-Pawelska ◽  
Kamil Ochał ◽  
Andrzej Gradzik ◽  
Danil Yurievich Pimenov ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Titanium Alloy ◽  
Electrochemical Impedance ◽  
Ti6al4v Alloy ◽  
Cutting Conditions ◽  
Practical Significance ◽  
Molar Ratio ◽  
Finish Turning ◽  
Ti6al4v Titanium Alloy

The influence of cooling conditions and surface topography after finish turning of Ti6Al4V titanium alloy on corrosion resistance and surface bioactivity was analyzed. The samples were machined under dry and minimum quantity lubrication (MQL) conditions to obtain different surface roughness. The surface topographies of the processed samples were assessed and measured using an optical profilometer. The produced samples were subjected to electrochemical impedance spectroscopy (EIS) and corrosion potential tests (Ecorr) in the presence of simulated body fluid (SBF). The surface bioactivity of the samples was assessed on the basis of images from scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis. The inspection of the surfaces of samples after turning under dry and MQL conditions revealed unevenly distributed precipitation of hydroxyapatite compounds (Ca/P) with a molar ratio in the range of 1.73–1.97. Regardless of the cutting conditions and surface roughness, the highest values of Ecorr ~0 mV were recorded on day 7 of immersion in the SBF solution. The impedance characteristics showed that, compared to the MQL conditions, surfaces machined under dry conditions were characterized by greater resistance and the presence of a passive layer on the processed surface. The main novelty of the paper is the study of the effect of ecological machining conditions, namely, dry and MQL cutting on the corrosion resistance and surface bioactivity of Ti6Al4V titanium alloy after finish turning. The obtained research results have practical significance. They can be used by engineers during the development of technological processes for medical devices made of Ti6Al4V alloy to obtain favorable functional properties of these devices.

Direct reduction of upgraded titania slag by magnesium for making low-oxygen containing titanium alloy hydride powder

2020 ◽  
Vol 368 ◽  
pp. 160-169
Author(s):  
Zhaowang Dong ◽  
Yang Xia ◽  
Xueyi Guo ◽  
Jinlong Zhao ◽  
Linfeng Jiang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Direct Reduction ◽  
Low Oxygen ◽  
Titania Slag ◽  
Hydride Powder

Fabrication and Compressive Properties of Porous Ti6Al4V Alloy with Elongated Pores for Biomedical Application

2015 ◽  
Vol 815 ◽  
pp. 354-358
Author(s):  
Fu Ping Li ◽  
Jin Shan Li ◽  
Ge Jun Liu ◽  
Hong Chao Kou ◽  
Guang Sheng Xu ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Biomedical Application ◽  
Bone Ingrowth ◽  
Porous Titanium ◽  
Ti6al4v Alloy ◽  
Anisotropic Structure ◽  
Compressive Properties ◽  
Out Of Plane ◽  
Plane Direction ◽  
Mechanical Compatibility

Porous Ti6Al4V alloys with anisotropic structure for biomedical application was fabricated by diffusion bonding of titanium alloy meshes. Compressive mechanical compatibility of the alloys is investigated as human bone implants. It is concluded that the fabrication processing for porous Ti6Al4V alloys has better control of the porosity. The pore structure of porous titanium is anisotropic, with elongated and square pores in the out-of-plane and in-plane direction, respectively, which is suited for bone ingrowth. The compressive Young’s modulus and yield stress of porous Ti6Al4V alloy compressed in the out-of-plane direction are 12.2 GPa and 171.4 MPa, respectively, which is compatible with those for the cortical bones.

scholarly journals Numerical Optimization Of The Gating System For An Inlet Valve Casting Made Of Titanium Alloy

2015 ◽  
Vol 60 (3) ◽  
pp. 2437-2446 ◽  
Author(s):  
J. Fourie ◽  
J. Lelito ◽  
P.L. Żak ◽  
P.K. Krajewski ◽  
W. Wołczyński
Keyword(s):  
Titanium Alloy ◽  
Numerical Optimization ◽  
Complex Geometry ◽  
Ti6al4v Alloy ◽  
Geometrical Parameters ◽  
Gating System ◽  
Slight Effect ◽  
Inlet Valve ◽  
Simple Geometry ◽  
Best Fit

AbstractThe main aim of this work was to numerically investigate and optimize feeding and geometrical parameters to produce inlet valves of Ti6Al4V alloy that are free from defects, especially porosity. It was found that the change of geometry orientation as well as inlet feeder diameter and angle showed distinct relationships between geometric alteration and occurrence of porosity. Alteration in the pouring parameters such as temperature and time had none or only slight effect on occurrence or position of porosity in the valve. It was also found that investigating individual parameters of simple geometry and then utilizing these best fit results in complex geometry yielded beneficial results that would otherwise not be attainable.

scholarly journals Bioactivity of Ti6Al4V alloy with bioglass and corrosion protection by silane coating

2021 ◽  
Vol 10 (6) ◽  
pp. e23310615308
Author(s):  
Patricia Marcolin ◽  
Caroline Olivieri da Silva Frozza ◽  
João Antonio Pêgas Henriques ◽  
Sandra Raquel Kunst ◽  
Murilo Camuri Crovace ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Metallic Substrate ◽  
Ti6al4v Alloy ◽  
Barrier Effect ◽  
Osteoblast Cells ◽  
Bioactive Coatings ◽  
Test Conditions ◽  
Silane Coating ◽  
Titanium Alloy Ti6al4v ◽  
Film Substrate

The Ti6Al4V alloy is usually employed as a biomaterial, however, when in use, exhibits a few drawbacks such as corrosion, caused by the release of aluminum and vanadium ions besides the bioinert behavior. Bioactive coatings offer a barrier effect and bioactivity, promoting biocompatibility and osseointegration processes. The present work aims to study the biocompatibility behavior of a bioglass-containing silane film deposited on a titanium alloy (Ti6Al4V) substrate. The effect of the surface roughness of the metallic substrate was also evaluated. Film/substrate systems were characterized as their morphological, chemical, physical, electrochemical behavior, and cell cytotoxicity and cell viability. The main results pointed out that silane films augment corrosion resistance of titanium alloy substrates. The biological results indicated a growth of osteoblast cells (MG-63), for all the test conditions. The bioglass film deposited on the ground substrate exhibits the highest cell density.

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