• Title/Summary/Keyword: titanium (Ti)

Search Result 1,963, Processing Time 0.034 seconds

Ultra-fine Grained and Dispersion-strengthened Titanium Materials Manufactured by Spark Plasma Sintering

  • Handtrack, Dirk;Sauer, Christa;Kieback, Bernd
    • Proceedings of the Korean Powder Metallurgy Institute Conference
    • /
    • 2006.09b
    • /
    • pp.725-726
    • /
    • 2006
  • Ultra-fine grained and dispersion-strengthened titanium materials (Ti-Si, Ti-C, Ti-Si-C) have been produced by high energy ball milling and spark plasma sintering (SPS). Silicon or/and carbon were milled together with the titanium powder to form nanometer-sized and homogeneously distributed titanium silicides or/and carbides as dispersoids, that should prevent grain coarsening during the SPS compaction and contribute to strengthening of the material. The microstructures and the mechanical properties showed that strength, hardness and wear resistance of the sintered materials have been significantly improved by the mechanisms of grain refinement and dispersion strengthening. The use of an organic fluid as carrier of the dispersoid forming elements caused a significant increase in ductility.

  • PDF

Formation of Ti-0 Biomedical Film on Ti6A14V Alloy by DC Glow Plasma Oxidizing

  • Zheng, C.L.;Cui, F.Z.;Xu, Z.
    • Journal of Korean Vacuum Science & Technology
    • /
    • v.6 no.1
    • /
    • pp.16-21
    • /
    • 2002
  • Ti-0 film is a kind of biocompatible surface materials. In this paper, a new method, glow discharge plasma oxidizing, has been used in synthesizing Ti-O gradient films on Ti6A14V substrates. The effects of ion bombardment and process parameters on the structures of titanium oxide layers have been investigated. The results demonstrate that DC glow plasma oxidizing is more efficient in preparation of dense, hard, and high adhesive Ti-O biomedical films on titanium and its alloys. Samples treated by this method show higher hardness values than by others. Especially, in the condition of hollow cathode discharge, the ion bombardment enhances ionization of oxygen, promotes the oxygen permeation and facilitates the formation of the oxide of low valence states of titanium.

  • PDF

Recent Trends of Friction Stir Welding of Titanium (타이타늄 소재 마찰교반용접 기술 동향)

  • Chun, Chang-Keun;Kim, Sung-Wook;Kim, Heung-Joo;Chang, Woong-Seong;Noh, Joong-Suk
    • Journal of Welding and Joining
    • /
    • v.31 no.2
    • /
    • pp.16-20
    • /
    • 2013
  • Titanium and its alloys have been widely using in the various field of industry application due to high corrosion resistant properties and mechanical properties. Titanium is highly reactive in the high temperature state and the formation of titanium oxide and porosities in the nuggets of fusion welding will results in the degradation of the mechanical properties. For this reason the studies of friction stir welding for titanium have been investigated recently. The FSW zones of titanium were classified by the weld nugget (WN), the linear transition boundary (TB) and the heat affected zone (HAZ). The WN along with titanium parent was characterized by the presence of twins and dislocations. The average grain size and hardness of WN has been changed according to heat input. The grain refinement resulted from the FSW increased the hardness in the stir zone. Sound dissimilar joints between SUS 304 and CP-Ti were achieved using an advancing speed of 50 mm/min and rotation speeds in the range of 700-1100 rpm. Aluminum 1060 and titanium alloy Ti-6Al-4V plates were lap joined by friction stir welding, hence the ultimate tensile shear strength of joint reached 100% of Al 1060. Mg alloy and Ti were successfully butt joined by inserting a probe into the Mg alloy plate with slightly offsetting. But Ti-Al intermetallic compound layers formed at the interface of these joints.

Study on blood compatibility of diamond-like carbon and titanium nitride films (Diamond-like carbon 및 titanium nitride 박막의 혈액적합성 연구)

  • Yun Ju-Young;Bae Jin-Woo;Park Ki-Dong;Goo Hyun-Chul;Park Hyung-Dal;Chung Kwang-Wha
    • Journal of the Korean Vacuum Society
    • /
    • v.14 no.3
    • /
    • pp.165-170
    • /
    • 2005
  • There is an increasing interest in developing novel coating to improve the blood compatibility of medical implants. Diamond-like carbon(DLC) and titanium nitride(TiN) films have been proposed as potential biomedical coatings due to their chemical k physical properties and moderate biocompatibility. To study the correlation between blood compatibility and physical properties of the films, the fibrinogen adsorption on the surface as well as morphology & wettability were investigated. The quantity of fibrinogen adsorption are Tower for TiN than DLC, which correlates with a higher hydrophilicity of TiN film. To reduce the quantity of fibrinogen adsorption on the film, plasma treatment and furnace annealing were performed, respectively. With the use of oxygen plasma and furnace annealing, the amount of fibrinogen adsorption on TiN film was remarkably reduced, while there was no decrease of the quantity with DLC.

Current Status of Titanium Smelting Technology (타이타늄 제련기술 현황)

  • Sohn, Ho-Sang;Jung, Jae-Young
    • Resources Recycling
    • /
    • v.25 no.4
    • /
    • pp.68-79
    • /
    • 2016
  • Titanium is the ninth most abundant element in the Earth's crust. It is also the forth most abundant structural metal after aluminum, iron and magnesium. Titanium is conventionally produced by the Kroll process. New processes to produce metallic titanium have been currently developed by many researchers in the world. In this study, the existing technologies, including both commercial and developmental processes, categorized into three groups: those by metallothermic reduction of $TiCl_4$ and $TiO_2$, those by electrolytic reduction of $TiO_2$ and hydrogen reduction of Ti compounds. Their mechanisms for reduction and their features are summarized and discussed in the view of industrial application.

Effect of Oxygen Content on Aging Properties of Ti-39Nb-6Zr alloy (Ti-39Nb-6Zr 합금의 산소함량에 따른 시효특성 변화)

  • Han, Chan Byeol;Lee, Dong-Geun
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.35 no.2
    • /
    • pp.88-95
    • /
    • 2022
  • Titanium alloy for bio-medical applications have been developed to reduce the toxicity of alloying elements and avoid the stress-shielding effect which is caused by relatively high elastic modulus compared to bone. Ti-39Nb-6Zr (TNZ40) alloy of elastic modulus exhibits around 40 GPa in the case of beta single phase. However, the strength of this alloy is lower than the other types of titanium alloys. Many research found that adding oxygen to beta-titanium alloys is beneficial for improving the strength through solid solution strengthening. In this study, TNZ40 ingots with addition of O were prepared by an arc remelting process (Ti-39Nb-6Zr-0.16O (wt.%), Ti-39Nb-6Zr-0.26O (wt.%)). Thermo-mechanical processing (i.e., heat treatment, cold swaging and aging heat treatment) has been performed under various conditions. Therefore, the aim of this study is to investigate the effect of oxygen content and ω phase formation on microstructure and mechanical properties.

Synthesis of Titanium Silicides by Mechanical Alloying (기계적합금화에 의한 Ti Silicide 화합물의 합성)

  • 변창섭;이상호;김동관;이진형
    • Journal of Powder Materials
    • /
    • v.5 no.4
    • /
    • pp.250-257
    • /
    • 1998
  • The synthesis of titanium silicides ($Ti_3Si$, $TiSi_2$, $Ti_5Si_4$, $Ti_5Si_3$ and TiSi) by mechanical alloying has been investigated. Rapid, self-propagating high-temperature synthesis (SHS) reactions were observed to produce the last three phases during room-temperature high-energy ball milling of elemental powders. Such reactions appeared to be ignited by mechanical impact in an intimate, fine powder mixture formed after a critical milling period. During the high-energy ball milling, the repeated impact at contact points leads to a local concentration of energy which may ignite a self-propagating reaction. From in-situ thermal analysis, each critical milling period for the formation of $Ti_5Si_4$, $Ti_5Si_3$ and TiSi was observed to be 22, 35.5 and 53.5 min, respectively. $Ti_3Si$ and $TiSi_2$, however, have not been produced even till the milling period of 360 min due to lack of the homogeneity of the powder mixtures. The formation of titanium silicides by mechanical alloying and the relevant reaction rates appeared to depend upon the critical milling period, the homogeneity of the powder mixtures, and the heat of formation of the products involved.

  • PDF

A STUDY ON THE RESISTANCE OF WEAR AND CYTOTOXICITY OF THE TITANIUM SURFACE AFTER FILM DEPOSITIONS (박막증착시 티타늄 표면의 마손저항도와 세포독성에 관한 연구)

  • Kim Hyung-Woo;Kim Chang-Whe;Kim Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.39 no.1
    • /
    • pp.84-95
    • /
    • 2001
  • Titanium is widely used in dentistry for its low density, high strength, fatigue resistance, corrosion resistance, and biocompatibility. But it has a tendency of surface damage under circumstance of friction and impact for its low hardness of the surface. Coating is one of methods fir increasing surface hardness. Its effect is to improve surface physical characteristics without change of titanium. Diamond-like carbon and titanium nitride are known for its high hardness of the surface. So that this study was aimed at the wear test and the cytotoxicity test of the commercially pure titanium and Ti-6Al-4V alloy which were deposited by diamond-like carbon film or titanium nitride film to acertain improvement of the surface hardness and the biocompatibility. A disk (25mm diameter, 2mm thickness) was made of commercially pure titanium and Ti-6Al-4V alloy and these substrates were deposited by diamond-like carbon film or titanium nitride film. Diamond-like carbon film was deposited by the method of radiofrequency plasma assisted chemical vapor deposition and titanium nitride film was deposited by the method of reactive arc ion plating. Then these substrates were tested about wear characteristics by the pin-on-disk type wear tester in which ruby ball was used as a wear causer under the load of 32N, The fracture cycles were measured by rotating the substrates until their films were fractured. The wear volume was measured after 150 cycles and 3,000 cycles using surface profiler. The cytotoxicity test was peformed by the method of the MTT assay. The results were as follows : 1. In the results of the wear volume test, commercially pure titanium and titanium alloy which were coated by diamond-like carbon film or titanium nitride aim had higher resistance against wear than the substrates which were not coated by any films (P<0.05). 2. In the results of the fracture cycle test and the wear volume test, diamond-like carbon film had higher resistance against wear than titanium nitride film (P<0.05). 3. In both coatings of diamond-like carbon aim and titanium nitride film, Ti-6Al-4V alloy had higher resistance against wear than commercially pure titanium (P<0.05) 4. In the results of the cytotoxicity test, diamond-like carbon film and titanium nitride film had little cytotoxicity as like commercially pure titanium or Ti-6Al-4V alloy (P>0.05).

  • PDF

Synthesis of $TiO_2$ Powders by the Hydrolysis of Titanium n-Butoxide and Reaction Mechanism (Titanium n-Butoxide의 가수분해에 의한 $TiO_2$ 분말 합성과 반응 메커니즘)

  • Park, J.K.;Myung, J.J.;Chung, Y.S.;Kyong, J.B.;Kim, H.K.
    • Journal of the Korean Chemical Society
    • /
    • v.43 no.5
    • /
    • pp.505-510
    • /
    • 1999
  • $TiO_2$ powders were prepared via hydrolysis of titanium n-butoxide in n-butanol and hydrolysis mechanism of titanium n-butoxide was studied using UV-Vis spectrometer. Hydrolysis reactions were controlled to proceed to pseudo-first order reaction in the presence of excess water. The phases of $TiO_2$ powders, prepared under the these conditions, were identified by XRD and reaction rates were calculated by Gugggenheim method. Prepared powders were noncrystalline states in their initial stage of formation but transformed to crystalline rutile structure by heating. Reaction mechanism of titanium n-butoxide was proposed as Interchange-Associative(Ia) mechanism, based on the data of n-value and termodynamic parameters which were determined from the rate constants.

  • PDF