• Title/Summary/Keyword: Ti-6Al-4V

Search Result 469, Processing Time 0.027 seconds

Comparing Resistances to Pitting Corrosion of Additive Manufactured Ti-6Al-4V Alloys in NaCl and NaBr Aqueous Solutions (NaCl과 NaBr수용액에서 적층가공으로 제조된 Ti-6Al-4V 합금의 공식 저항성 비교)

  • Seo, Dong-Il;Lee, Jae-Bong
    • Corrosion Science and Technology
    • /
    • v.18 no.3
    • /
    • pp.110-116
    • /
    • 2019
  • Resistances to pitting corrosion of additive manufactured (AM) Ti-6Al-4V alloys in 0.6 M NaBr and 0.6 M NaCl aqueous solutions were compared using micro-droplet cell techniques. With respect to the pitting corrosion resistance, this study focused on two different types of halide anions in aqueous solutions, i.e. $Br^-$ and $Cl^-$. The differences between $Br^-$ and $Cl^-$ halide anions for breakdown on passive films of AM Ti-6Al-4V alloy were explained using Langmuir adsorption model with their equilibrium adsorption coefficients. The results of the analysis showed that the lower resistance to pitting potential of AM Ti-6Al-4V alloy in $Br^-$ aqueous solution was attributed to the higher equilibrium adsorption coefficient of Br-. In addition, micro-electrochemical test results showed that the pitting corrosion resistance of dark grains in additive manufactured Ti-6Al-4V alloy was lower as compared to that of bright grains due to the larger volume of ${\alpha}^{\prime}$ phase that caused the susceptibility to pit initiation.

Effect of Annealing Treatment on Microstructure and Hydrogen Embrittlement of Ti-6Al-4V Alloys Subject to Electrochemical Hydrogen Charging (전기화학적 수소 주입에 의한 Ti-6Al-4V 합금의 미세조직과 수소 취성에 미치는 어닐링 처리의 영향)

  • Ko, S.W.;Lee, J.M.;Kwon, Y.N.;Hwang, B.
    • Transactions of Materials Processing
    • /
    • v.29 no.4
    • /
    • pp.211-217
    • /
    • 2020
  • This paper presents a study on the hydrogen embrittlement of Ti-6Al-4V alloys with different microstructures depending on annealing treatment. They were electrochemically charged with hydrogen and subjected to tensile tests to investigate hydrogen embrittlement behavior. Tensile test results showed that the elongation of Ti-6Al-4V alloy specimens was remarkably decreased with increasing the volume fraction of β phase after hydrogen charging. This is because the β phase with a relatively low diffusivity tends to easily form a hydride at grain boundaries during electrochemical hydrogen charging. After hydrogen charging of the Ti-6Al-4V alloy specimen, it found that silver particles were decorated mostly at the grain boundary, and coarser silver particles were usually formed in the specimen annealed at 950 ℃. Therefore, the specimen having higher β phase fraction shows a poor hydrogen embrittlement resistance because the β phase promotes the formation of coarse hydride during electrochemical hydrogen charging, which leads to a large decrease in ductility.

Effects of Wollastonite Coating on Surface Characteristics of Plasma Electrolytic Oxidized Ti-6Al-4V Alloy (플라즈마 전해 산화처리된 Ti-6Al-4V합금의 표면특성에 미치는 울라스토나이트 코팅효과)

  • Jaeeun Go;Jong Kook Lee;Han Cheol Choe
    • Corrosion Science and Technology
    • /
    • v.22 no.4
    • /
    • pp.257-264
    • /
    • 2023
  • Ti-6Al-4V alloys are mainly used as dental materials due to their excellent biocompatibility, corrosion resistance, and chemical stability. However, they have a low bioactivity with bioinertness in the body. Therefore, they could not directly bond with human bone. To improve their applications, their bone bonding ability and bone formation capacity should be improved. Thus, the objective of this study was to improve the bioinert surface of titanium alloy substrate to show bioactive characteristics by performing surface modification using wollastonite powder. Commercial bioactive wollastonite powder was successfully deposited onto Ti-6Al-4V alloy using a room temperature spray process. It was found that wollastonite-coated layer showed homogeneous microstructure and uniform thickness. Corrosion resistance of Ti-6Al-4V alloy was also improved by plasma electrolytic oxidation treatment. Its wettability and bioactivity were also greatly increased by wollastonite coating. Results of this study indicate that both plasma electrolytic oxidation treatment and wollastonite coating by room temperature spray process could be used to improve surface bioactivity of Ti-6Al-4V alloy substrate.

Process Design for Profile Ring Rolling of Ti-6Al-4V Alloy (Ti-6Al-4V합금의 형상 링 압연 공정설계)

  • Yeom, J.T.;Kim, J.H.;Lee, D.G.;Park, N.K.;Choi, S.S.;Lee, C.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2007.05a
    • /
    • pp.357-360
    • /
    • 2007
  • The profile ring rolling process of Ti-6Al-4V alloy was designed by finite element(FE) simulation and experimental analysis. The design includes geometry design and optimization of process variables. The geometry design such as initial billet and blank sizes, and final rolled ring shape was carried out with the calculation method based on the uniform deformation concept between the wall thickness and ring height. FEM simulation was used to calculate the state variables such as strain, strain rate and temperature and to predict the formation of forming defects during ring rolling process. Finally, the mechanical properties of profiled Ti-6Al-4V alloy ring product were analyzed with the evolution of microstructures during the ring rolling process.

  • PDF

The Effect of Microstructure on the Static and Dynamic Deformation Behavior of Ti-6Al-4V Alloy (Ti-6Al-4V 합금의 미세조직에 따른 정적 및 동적 변형에 관한 연구)

  • Lee D. G.;Lee Y. H.;Lee S. H.;Hur S. M.;Lee C. S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2001.10a
    • /
    • pp.277-280
    • /
    • 2001
  • The effects of a -phase morphology on the static and dynamic deformation behavior of a Ti-6Al-4V alloy was investigated in this study. Static tension test, static and dynamic tension test and hot compression test were conducted on three microstructures of Ti-6Al-4V alloy, i.e., equiaxed, widmanstatten and bimodal microstructures. Fracture surfaces of all three microstructures represented ductile fracture appearance, though the formation of adiabatic shear bands was noticed at dynamic torsion test. The susceptibility of forming adiabatic shear bands was greatest in the equiaxed microsoucture and lowest in the bimodal microstructure, which was evidenced by hot compression test.

  • PDF

Brazing of metal-coated $ZrO_2$ and Ti-6Al-4V (금속 표면 코팅된 $ZrO_2$와 Ti-6Al-4V의 접합)

  • No, Myeong-Hun;Jeong, Jae-Pil;Kim, Won-Jung;Kim, In-Ho
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2011.05a
    • /
    • pp.187-187
    • /
    • 2011
  • 지르코니아 ($ZrO_2$) 표면에 금속 (Au)으로 표면 코팅한 후 Ti-6Al-4V와 진공 브레이징 접합을 행하였다. 표면에 코팅한 Au 층의 영향을 비교 분석하기 위하여 Au를 코팅하지 않은 지르코니아도 모재로 사용하였다. 접합소재로는 Ag-Cu-Ti계 active filler를 사용하였다. $ZrO_2$/Ti-6Al-4V 브레이징 결과, active filler는 양측 모재 표면에 wetting 되었으며, Ti-6Al-4V 내부로 filler 확산으로 인하여 두 모재의 direct joint가 관찰되었다. 접합 계면 사이에 접합부 결함은 관찰되지 않았다.

  • PDF

The Effect of Hardening Methods and Process Parameters on Surface Hardening of Ti-6Al-4V Alloy (Ti-6Al-4V 합금의 표면 경화 시 경화기구 및 공정변수가 표면 경화에 미치는 영향)

  • Seo, D.M.;Y., H. Jeong;Hwang, T.W.;Moon, Y.H.
    • Transactions of Materials Processing
    • /
    • v.28 no.1
    • /
    • pp.27-33
    • /
    • 2019
  • The effect of hardening methods and process parameters on surface hardening of a Ti-6Al-4V Alloy has been investigated in this study. To characterize the effectiveness of the respective surface hardening methods, samples of a Ti-6Al-4V alloy were self-quenched, laser-nitrided, laser-carburized, laser-carbonitrided at the same laser irradiation conditions. This experimental procedure was followed by comparing the microstructural evolutions and mechanical properties of the respective samples after the laser surface hardenings. The hardening characteristics of the respective laser surface hardenings were well defined in this study, and the hardness was significantly influenced by the reaction compounds and laser energy density.

Characterizations of Ti-Al-V-N Films Deposited by DC and RF Reactive Magnetron Sputtering (직류 및 고주파 마그네트론 스퍼터링법으로 증착한 Ti-Al-V-N 박막의 특성)

  • Sohn, Yong-Un;Chung, In-Wha;Lee, Young-Ki
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.13 no.6
    • /
    • pp.398-404
    • /
    • 2000
  • The Ti-Al-V-N films have been deposited on various substrates by d.c and r.f reactive magnetron sputtering from a Ti-6Al-4V alloy target in mixed $Ar-N_2$ discharges. The films were investigated by means of XRD, AES, SEM/EDX, microhardness, TG and scratch test. The XRD and SEM results indicated that the films were of single B1 NaCl phase having dense columnar structure with the (111) preferred orientation. The composition of Ti-Al-V-N film was the Ti-7.1Al-4.3V-N(wt%) films. Adhesion and microhardness of Ti-Al-V-N films deposited by r.f magnetron sputtering method were better than those deposited by d.c magnetron sputtering method. The anti-oxidation properties of Ti-Al-V-N films were also superior to that of Ti-N film deposited by the same deposition conditions.

  • PDF

Solid-state sintering mechanism of blended elemental Ti-6Al-4V powders

  • Kim, Youngmoo;Song, Young-Beom;Lee, Sung Ho
    • Journal of Powder Materials
    • /
    • v.25 no.2
    • /
    • pp.109-119
    • /
    • 2018
  • The objective of this study is to reveal the sintering mechanism of mixed Ti-6Al-4V powders considering the densification and the homogenization between Ti and Al/V particles. It is found that the addition of master alloy particles into Ti enhances densification by the migration of Al into the Ti matrix prior to the self-diffusion of Ti. However, as Ti particles become coarser, sintering of the powders appears to be retarded due to slower inter-diffusion of the particles due to the reduced surface energies of Ti. Such phenomena are confirmed by a series of dilatometry tests and microstructural analyses in respect to the sintering temperature. Furthermore, the results are also consistent with the predicted activation energies for sintering. The energies are found to have decreased from 299.35 to $135.48kJ{\cdot}mol^{-1}$ by adding the Al/V particles because the activation energy for the diffusion of Al in ${\alpha}-Ti$ ($77kJ{\cdot}mol^{-1}$) is much lower than that of the self-diffusion of ${\alpha}-Ti$. The coarser Ti powders increase the energies from 135.48 to $181.16kJ{\cdot}mol^{-1}$ because the specific surface areas of Ti decrease.

A HISTOMORPHOMETRIC STUDY OF BONE APPOSITION TO NEWLY DEVELOPED TI-BASED ALLOYS IN RABBIT BONE (가토의 경골에 이식된 새로운 티타늄계 합금 주위의 골형성에 관한 형태학적 연구)

  • Kim, Tae-In
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.36 no.5
    • /
    • pp.701-720
    • /
    • 1998
  • Research advances in dental implantology have led to the development of several different types of materials and it is anticipated that continued research will lead to advanced dental implant materials. Currently used pure titanium has relatively low hardness and strength which may limit its ability to resist functional loads as a dental implant. Ti-6Al-4V also has potential problems such as corrosion resistance. osseointegration properties and neurologic disorder due to aluminium and vanadium, known as highly toxic elements, contained in Ti-6Al-4V. Newly developed titanium based alloys(Ti-20Zr-3Nb-3Ta-0.2Pd-1In, Ti-20Zr-3Nb-3Ta-0.2Pd) which do not contain toxic metallic components were designed by the Korea Institute of Science and Technology (KIST) with alloy design techniques using Zr, Nb, Ta, Pd, and In which are known as non-toxic elements. Biocompatibility and osseointegration properties of these newly designed alloys were evaluated after implantation in rabbit femur for 3 months. The conclusions were as follows : 1. Mechanical properties of the new designed Ti based alloys(Ti-20Zr-3Nb-3Ta-0.2Pd-1In, Ti-20Zr-3Nb-3Ta-0.2Pd) demonstrated close hardness and tensile strength values to Ti-6Al-4V. 2. New desinged experimental alloys showed stable corrosion resistance similar to the pure Ti but better than Ti-6Al-4V. However, the corrosion rate was higher for the new alloys. 3. Cell culture test showed that the new alloys have similar cell response compared with pure Ti and Ti-6Al-4V with no cell adverse reaction. 4. New designed alloys showed similar bone-metal contact ratio and osseointegration properties compared to pure Ti and Ti-6Al-4V after 3 months implantation in rabbit femur. 5. Four different surface treatments of the metals did not show any statistical difference of the cell growth and bone-metal contact ratio.

  • PDF