Surface characteristics of titanium–silver alloys in artificial saliva

Shim, H. M.,Oh, K. T.,Woo, J. Y.,Hwang, C. J.,Kim, K. N. Heyden & Son 2006 Surface and interface analysis Vol.38 No.1

<P>Titanium and its alloys are widely used in biomedical and dental fields because of their excellent corrosion resistance and biocompatibility. It is well known that titanium is protected from corrosion because of the stability of the passive film that controls and determines the corrosion resistance and biocompatibility of titanium and its alloys. The purpose of this study was to evaluate the electrochemical properties of titanium–silver alloys and the surface characteristics of passive film in artificial saliva.</P><P>We designed titanium–silver alloys with silver contents ranging from 0 to 5 at.%, in 1% increments. These alloys were arc-melted, homogenized, hot-rolled to 2 mm thickness, and finally solution heat-treated for 1 h and quenched. Potentiostatic testing was performed, and the open circuit potentials of the alloys were measured in artificial saliva, at 37 °C. The passive films of the titanium–silver alloys were analyzed via XPS.</P><P>Titanium–silver alloys maintained low current density and showed stable passive region and also had high open circuit potential as compared with pure titanium. The open circuit potential of titanium–silver alloys increased as silver addition increased. With regard to the fraction of oxygen species, a component of over 80% was found to be comprised of oxide. Therefore, the titanium surface mainly consisted of titanium oxide and, on the titanium–silver alloys, this film was composed of TiO<SUB>2</SUB>, Ti<SUB>2</SUB>O<SUB>3</SUB>, and TiO. As silver content increased, the TiO<SUB>2</SUB> fraction also increased, as did the thickness of the titanium oxide layer formed. Copyright © 2005 John Wiley & Sons, Ltd.</P>

Brief review of removal effect of hydrogen-plasma arc melting on refining of pure titanium and titanium alloys

Oh, J.M.,Roh, K.M.,Lim, J.W. Pergamon Press ; Elsevier Science Ltd 2016 International journal of hydrogen energy Vol.41 No.48

<P>In this study, the effect of hydrogen-plasma arc melting (HPAM) on the removal of metallic and gaseous impurities from pure titanium and titanium alloys is briefly reviewed according to the previous results and a newly added experiment. The highest removal degree (RD) of metallic impurities from pure titanium by HPAM with an Ar-20 vol.% of H-2 gas is 84.8%. In the titanium alloys, the RD values of the metallic impurities of the Ti-Ni, Ti-Mo, Ti-Al, and Ti-6A1-4V alloys regarding HPAM with an Ar-20 vol.% of H-2 gas are 82.6%, 86.2%, 49.1%, and 76.6%, respectively. The total amount of gaseous impurities such as O, N, C, and H was decreased to 962 ppm from 2697 ppm, whereby a high RD value of 64.6% is shown despite the strong affinity of titanium regarding gaseous elements. It is suggested that HPAM exerts a dramatic effect on the removal of metallic impurities from pure titanium and titanium alloys, and it is appropriate for the refining of titanium alloys whereby a significant weight loss needs to be avoided. Thereby, HPAM process can be applied to industrial refining of commercial titanium and titanium alloys. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.</P>

원심 주조된 타이타늄과 타이타늄 합금의 레이저 용접 특성

윤미경,김현승,양홍서,방몽숙,박상원,박하옥,이광민,Yun, Mi-Kyung,Kim, Hyun-Seung,Yang, Hong-So,Vang, Mong-Sook,Park, Sang-Won,Park, Ha-Ok,Lee, Kwang-Min 대한치과보철학회 2006 대한치과보철학회지 Vol.44 No.5

Purpose : The purpose of this study was to investigate the effect of the output energy(voltage) of laser welding on the strength and properties of joint of cast titanium(CP Gr II) and titanium alloy(Ti-6Al-4V). Material and method : Cast titanium and its alloy rods(ISO6871) were prepared and perpendicularly cut at the center of the rod. After the cut halves were fixed in a jig, and the joints welded with a laser-welding machine at several levels of output voltage of $200V{\sim}280V$. Uncut specimens served as the non-welded control specimens The pulse duration and pulse spot size employed in this study were 10ms and 1.0mm respectively. Tensile testing was conducted at a crosshead speed of 0.5mm/min. The ultimate tensile strength(MPa) was recorded, and the data (n=6) were statistically analyzed by one-way analysis of variance(ANOVA) and Scheffe's test at ${\alpha}$=0.05. The fracture surface of specimens investigated by scanning electron microscope (SEM). Vickers microhardness was measured under 500g load of 15seconds with the optimal condition of output voltage 280V. Results : The results of this study were obtained as follows, 1. When the pulse duration and spot size were fixed at 10ms and 1.0mm respectively, increasing the output energy(voltage) increased UTS values and penetration depth of laser welded to titanium and titanium alloy. 2. For the commercial titanium grade II, ultimate tensile strength(665.3MPa) of the specimens laser-welded at voltage of 280V were not statistically(p>0.05) different from the non-welded control specimens (680.2MPa). 3. For the titanium alloy(Ti-6Al-4V), ultimate tensile strength(988.3MPa) of the specimens laser-welded at voltage of 280V were statistically(p<0.05) different from the non-welded control specimens (665.0MPa). 4. The commercial titanium grade II and titanium alloy(Ti-6Al-4V) were Vickers microhardness values were increased in the fusion zone and there were no significant differences in base metal, heat-affected zone.

Burn-resistant Coatings Lubricated on the Surface of Titanium Alloys

Pingze Zhang,Jun Huang,Hongyan Wu,Qiang Miao,Zhengjun Yao,Zhong Xu,Zhiyong He 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.-

Conventional titanium alloy may be ignited and burnt in conditions of high temperature, high air pressure, and high gas flow velocity. In the present study, burn-resistant coatings have been lubricated by using double glow plasma surface alloying technology. Alloying elements Cr, Mo, and Cu were induced into Ti6Al4V and Ti6.5Al0.3Mo1.5Zr0.25Si substrates through double glow discharged plasma processing, and Ti-Cr, Ti-Mo, and Ti-Cu burn-resistant alloy layers were formed on the surface of the Ti6Al4V and Ti6.5Al0.3Mo1.5Zr0.25Si alloys. The depth of the surface burn-resistant alloy layers could exceed 200 μm and the alloying-element component could reach 90%. Burn-resistant performance experimental results show that if the Cr component(wt%) is over 14%, the Cu component is over 12%, and the Mo component is over 10% in the alloying layers, ignition and burn of titanium alloy are effectively avoided. Conventional titanium alloy may be ignited and burnt in conditions of high temperature, high air pressure, and high gas flow velocity. In the present study, burn-resistant coatings have been lubricated by using double glow plasma surface alloying technology. Alloying elements Cr, Mo, and Cu were induced into Ti6Al4V and Ti6.5Al0.3Mo1.5Zr0.25Si substrates through double glow discharged plasma processing, and Ti-Cr, Ti-Mo, and Ti-Cu burn-resistant alloy layers were formed on the surface of the Ti6Al4V and Ti6.5Al0.3Mo1.5Zr0.25Si alloys. The depth of the surface burn-resistant alloy layers could exceed 200 μm and the alloying-element component could reach 90%. Burn-resistant performance experimental results show that if the Cr component(wt%) is over 14%, the Cu component is over 12%, and the Mo component is over 10% in the alloying layers, ignition and burn of titanium alloy are effectively avoided.

생체용 Ti-Ta-Mo-Zr 합금 개발에 관한 연구

원대희 한국기계기술학회 2016 한국기계기술학회지 Vol.18 No.3

This study was purposed to develope a titanium alloy with low elastic modulus to be used as dental implant. The new titanium alloy was prepared as titanium alloy by adding Tantalum(Ta), Zirconium(Zr), Molybdenum(Mo) into the Ti-X-Y-Z system alloys. In designing the new titanium alloys, two physical variables bond order (Bo) and d-electron orbit energy level (Md) were varied. Mean bond order ( ) was around 2.818∼2.8784eV, and Mean d-electron orbit energy level ( ) was 2.4541~2.4747eV. In the cases of titanium alloys of T-3M and T-3Z, the XRD analysis showed β phase. On the other hand, the phase of α+ β were observed in the T-6Z and T-8Z alloys. Exhibited the highest hardness value to result in T-3Z 309.7Hv alloy Vickers hardness with respect to titanium alloy. In the resulting T-3Z alloy of measuring the elastic modulus value for a titanium alloy exhibited the smallest modulus of elasticity value to 89.81GPa. TEM analysis identified additional feature for T-3Z alloy was detected in addition to the ß-phase.

치과주조용 Ti-Zr-Cr계 합금에서 Cr 함량변화가 부식저항성에 미치는 영향

박영준,강후원,이용렬,송호준,김민강 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.4

The purpose of this study was to develop new dental casting titanium (Ti) alloys having an excellent mechanical properties and good corrosion resistance as a substitute for c.p Ti and Ti-6Al-4V alloy (control groups). Ti-20Cr, Ti-2OZr and Ti-20Zr-XCr (X=2, 5, 10, 15) alloys (experimental groups) were designed for dental casting Ti alloys. Prior to casting prccedure, mother alloys were prepared by using vacuum arc melting with skull melting method. Argon-arc melting and argon/vacuum-pressure casting machine were used for making the specimens. The hardness, microstructure, and corrosion resistance were evaluated by using Vickers microhardness measurement, FE-SEM, and anodic polarization test. The results were as follows: 1. The Vickers microhardness (Hv) of Ti and Ti-6Al-4V alloy showed the values of 210 and 352, and Ti-20Cr and Ti-20Zr alloys showed the values of 341 and 259, respectively. As the Cr content increased from 0 to 15 % in Ti-20Zr-XCr (X=0, 2, 5, 10, 15) alloys, the Hv increased from 259 to 298, 457, 344, and 351, respectively. The microstructure of Ti-20Zr-XCr specimens showed significant difference by the concentration changes of Cr content showing acicular crystalline structure for Ti-20Zr-2Cr and Ti-20Zr-5Cr, and equiaxed crystalline structure for Ti-20Zr-10Cr and Ti-20Zr-15Cr. 2. Open-circuit potentials (E_(∝)) were rapidly decreased followed by steadiness as time elapse in all experimental groups except in Ti-20Z group. Ti-2OZr group showed an increase in E_(∝), from the first. 3. In potentiodynamic anodic polarization tests, all experimental groups showed more noble corrosion potential (E_(corr) than that of Ti-6Al-4V, and more basic E_(corr) than that of Ti. Especially, Ti-20Zr-10Cr alloy showed most favorable corrosion resistance among Ti-Zr-Cr alloys. 4. For Ti-20Zr-10Cr, Ti-20Zr-15Cr, and Ti-20Cr groups, which have more than 10% Cr content, the secondary corrosion potential shifted to noble direction in larger amounts than in the cases of control and other experimental groups. From these results, it was concluded that newly formulated Ti-20Zr-10Cr experimental alloy have adequate hardness and high corrosion resistance, and this alloy is promising candidate for a successful dental casting alloy.

불소이온에 따른 치과용 티타늄의 표면조도에 관한 연구

황경란,김철위 대한치과기재학회 1996 대한치과재료학회지 Vol.23 No.2

Titanium has a number of advantages, such as light weight, adequate strength, good corrosion resitance, excellent biocompatibility and reasonable price. Therefore, the wrought forms of titanium metals have been widely utilized in the dental field, including orthodontic wire and endosseous dental implants. Titanium exhibits exellent resistance to to most corrosive agents, but its passivated oxide layer is susceptible to halogens - especially fluorine and fluoride compounds. Prophylactic fluids and gels containing fluorides cause corrosion and surface alterations of titanium implant or prostheses. This study described the effects of fluoride ion on surface roughness of titanium. Five kinds of metals such as 2 kinds of commercially pure titanium, titanium-alumium-vanadium alloy, nickel-titanium and cobalt-chromium-molybdenum alloy were used. Alloys were embedded in cold-curing acrylic resin and polished with silicone carbide paper from # 800 to # 1,200. Specimens were cleaned with ethanol before further treatment. The surface roughness were measured for 0,1,5,10,20,40 minuite storage in sodium fluoride gel (1.23%, 0.62%, 0.41% fluoride ion) after rinsing with distilled water using surface roughness tester (Surtronic 3P, Rank Tayler Hobson, England). From the experiment, the following results were obtained: 1. The surface roughness of commercially pure titanium increased with fluoride concentration and storage time (p<0.01). 2. The surface roughness of titanium-allumium-vanadium alloy increased with fluoride concentration in 1.23% and 0.62% (p<0.01) and strage time but there was no significant difference with storage time in 0.41% fluoride ion (p>0.01). 3. In case of nickel-titanium alloy there was no significant difference in surface roughness depending on used fluoride concentration and storage time(p>0.01). 4. In case of cobalt-chromium- molybdenum alloy there was no significant difference in surface roughness in all experimental conditions(p>0.01).

Preparation of low oxygen content alloy powder from Ti binary alloy scrap by hydrogenation-dehydrogenation and deoxidation process

Oh, J.M.,Roh, K.M.,Lee, B.K.,Suh, C.Y.,Kim, W.,Kwon, H.,Lim, J.W. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.593 No.-

The present study describes the process of producing low oxygen content alloy powder from β titanium alloy scrap using hydrogenation-dehydrogenation (HDH) and deoxidation in solid state (DOSS) processes. β titanium alloys Ti-Mo and Ti-V with weight ratios of 9:1 and 8:2, respectively, were used to carry out the experimental work. In cases of both the Ti-Mo and the Ti-V alloys, high-quality alloy powders were produced by the HDH process, and it was confirmed that the hydrogenation process of titanium alloy showed lower exothermal temperatures than that of commercially pure (CP) titanium. The oxygen content of the manufactured Ti-Mo and Ti-V alloy powders were 3230 and 3090ppm, respectively. Subsequently, low oxygen Ti-Mo and Ti-V alloy powders were produced by the DOSS process; the oxygen content of these powders was 1000 and 870ppm, respectively. These concentration levels were confirmed to be considerably low as compared to those of commercial Ti-Mo and Ti-V alloy powders with oxygen content of 2750 and 3340ppm, respectively.

열처리된 티타늄 합금의 연삭가공 특성

허순,김원일,왕덕현,이윤경 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

A use of Titanium alloy as a structural material is increasing lately. Among those titanium alloys, Ti-6A1-4V alloy is the most popular one with taking 2/3 of it's market. Also, Ti-6AI-4V alloy can get the stability of organization and product measure, and the evaluation of the cutting ability and the mechanical characteristics. The point in titanium alloy work is on how treat the heat generated during grinding. Because the heat conductivity of titanium alloy is unnegligibly low, the grinding heat is accumulated in workpiece, and it cause the increasing of grinding grits' wear and the rough grinding surface. So, these characteristics in grinding of titanium alloy will change the mechanical characteristics of the titanium alloy. From this study, the mechanical characteristics of annealed Ti-6A1-4V alloy after grinding was concerned with checking out the bending strength values, and the factor of the change and the difference was analyzed after analyzing the surface roughness and the image from SEM.

Platelet-Rich Plasma Pretreatment on Grit-Blasted Titanium Alloy for Enhanced Osteogenic Differentiation of Human Adipose-Derived Stem Cells

홍성화,남진우,김희중,유정준 대한정형외과학회 2019 Clinics in Orthopedic Surgery Vol.11 No.3

Background: Adequate bone formation around titanium alloy implants is integral to successful implantation surgery. Stem cell–coated implants may accelerate peri-implant bone formation. This study investigates the effect of platelet-rich plasma (PRP) pretreatment on a titanium-alloy surface in terms of proliferation and osteogenic differentiation of human adipose-derived stem cells (hADSCs). Methods: Allogenic leukocyte-depleted PRP was obtained from blood supernatants. The hADSCs were isolated from thigh subcutaneous fat tissue. Grit-blasted titanium plugs were used in two different groups. In one group, 200 μL of PRP was added to the grit-blasted titanium plugs. The hADSCs were seeded in two groups: grit-blasted titanium plugs with or without PRP. The number of hADSCs was measured after 4 hours, 3 days, and 7 days of culture using Cell Counting Kit-8. Osteogenesis of hADSCs was measured by using an alkaline phosphatase activity assay on days 7 and 14, and a calcium assay on days 14 and 21. Osteogenic gene expression was measured by using reverse transcription polymerase chain reaction analysis of alkaline phosphatase, osteocalcin, and type I collagen mRNA. The microscopic morphology of grit-blasted titanium plugs with or without PRP was examined with a field-emission scanning electron microscope using a JSM-7401F apparatus on days 1 and 7. Results: Proliferation and osteogenic differentiation of hADSCs were found to be significantly higher on the grit-blasted titanium alloy preprocessed with PRP than the same alloy without pretreatment. Furthermore, a structural fibrillar mesh developed compactly on the grit-blasted titanium alloy with the PRP pretreatment. Conclusions: Our results demonstrate that a hADSC-based approach can be used for tissue-engineered peri-implant bone formation and that PRP pretreatment on the grit-blasted titanium alloy can improve proliferation and osteogenic differentiation of hADSCs.