Highly Ordered Nanotube Formation on Beta Typed Ti–xTa Alloy Surface

2020 ◽  
Vol 20 (9) ◽  
pp. 5791-5795
Author(s):  
Seung-Pyo Kim ◽  
Han-Cheol Choe
Keyword(s):  
Surface Characterization ◽  
Melting Furnace ◽  
Power Source ◽  
Alloy Surface ◽  
Vacuum Arc ◽  
X Ray ◽  
Dc Power ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Martensite Structure

In this study, the highly ordered nanotube formation on beta typed Ti–xTa alloy surface was investigated. The Ti–xTa binary alloys were manufactured using a vacuum arc-melting furnace with varying Ta contents (10, 30, and 50 wt%), and then homogenized by heat treatment at 1050 °C for 1 h. The nanotube formation of Ti–xTa (x = 10–50 wt%) alloys were performed using a DC power source of 30 V in 1.0 M H3PO4 + 0.8 wt% NaF electrolyte solution for 2 hrs. The surface characterization was performed using field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The microstructure of Ti–xTa alloy showed martensite structure α′, α″-phase, and a ′-phase structure. As the Ta content increased, the needle-like structures of α′ and α′-phase gradually disappeared and only the equiaxed structure of β-phase appeared. Nanotube morphology of Ti–xTa alloy changed according to Ta content. As the Ta content increased, the size of the nanotubes decreased and the number of the smaller nanotubes increased. In the cross-sectioned nanotube layer, the gap size between the nanotubes decreased as the Ta content increased.

Microstructure and Mechanical Properties of VTaTiMoAlx Refractory High Entropy Alloys

2017 ◽  
Vol 898 ◽  
pp. 638-642 ◽  
Author(s):  
Dong Xu Qiao ◽  
Hui Jiang ◽  
Xiao Xue Chang ◽  
Yi Ping Lu ◽  
Ting Ju Li
Keyword(s):  
Mechanical Properties ◽  
Vacuum Arc ◽  
High Entropy Alloys ◽  
X Ray Diffraction ◽  
Dendrite Structure ◽  
X Ray ◽  
High Entropy ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Microstructure And Mechanical Properties

A series of refractory high-entropy alloys VTaTiMoAlx with x=0,0.2,0.6,1.0 were designed and produced by vacuum arc melting. The effect of added Al elements on the microstructure and mechanical properties of refractory high-entropy alloys were investigated. The X-ray diffraction results showed that all the high-entropy alloys consist of simple BCC solid solution. SEM indicated that the microstructure of VTaTiMoAlx changes from equiaxial dendritic-like structure to typical dendrite structure with the addition of Al element. The composition of different regions in the alloys are obtained by energy dispersive spectroscopy and shows that Ta, Mo elements are enriched in the dendrite areas, and Al, Ti, V are enriched in inter-dendrite areas. The yield strength and compress strain reach maximum (σ0.2=1221MPa, ε=9.91%) at x=0, and decrease with the addition of Al element at room temperature. Vickers hardness of the alloys improves as the Al addition.

Plasma Electrolytic Oxidation on Ti–xNb–2Ag–2Pt Alloys for Nano- and Micro-Pore Formation in Electrolyte with Ca and P Ions for Dental Implant Use

2021 ◽  
Vol 21 (7) ◽  
pp. 3753-3758
Author(s):  
Hyun-Jun Kim ◽  
Han-Cheol Choe
Keyword(s):  
Dental Implant ◽  
Plasma Electrolytic Oxidation ◽  
Pore Formation ◽  
Melting Furnace ◽  
Vacuum Arc ◽  
X Ray ◽  
Arc Melting ◽  
Electrolytic Oxidation ◽  
Nb Content ◽  
Plasma Electrolytic

In this study, plasma electrolytic oxidation (PEO) on Ti–xNb–2Ag–2Pt alloys for nano- and micro-pore formation in electrolyte with Ca and P ions for dental implant use was studied using various experimental equipment. The Ti–xNb–2Ag–2Pt alloys were fabricated using a vacuum arc melting furnace, and micro-pores were created through PEO-treatment in an electrolyte containing Ca and P ions. The PEO-treated surface was observed by X-ray diffractometer (XRD), field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy (EDS). The microstructure of Ti– xNb–2Ag–2Pt alloys showed the transformation of needle-like structure to equiaxed structure, as Nb content increased. Adding small amounts of Ag and Pt to Ti–xNb alloys, microstructure was not observed the significantly difference compared to Ti–xNb. The nano- and micro-pore sizes increased as the Nb content increased after PEO-treatment of Ti-xNb. In the case of Ti–50Nb–2Ag–2Pt, groove structure was observed, also the Ca/P ratio increased as the Nb content increased. The oxide layer thickness of Ti–xNb–2Ag–2Pt alloys was increased, as the Nb content increased.

Study on Homogenization Time and Cooling Rate on Microstructure and Hardness of Ni-42.5wt%Ti-3wt%Cu Alloy

2010 ◽  
Vol 297-301 ◽  
pp. 489-494 ◽  
Author(s):  
A. Etaati ◽  
Ali Shokuhfar ◽  
E. Omrani ◽  
P. Movahed ◽  
H. Bolvardi ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Hardness Test ◽  
Vacuum Arc ◽  
Melting Method ◽  
X Ray ◽  
Cu Alloy ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Homogenization Time ◽  
Cooling Media

Over the last decades, numerous investigations have been conducted on Nitinol properties. However, the effects of alloying elements on Ni-rich NiTi alloys have been considered less. In this research, different effects of homogenization time and cooling rate on the behaviors of Ni-42.5wt%Ti-3wt%Cu alloy were evaluated. The mentioned alloy was fabricated by vacuum arc melting method. Three different homogenization times (half, one and two hours) and three cooling media (water, air and furnace) were selected. The microstructure and hardness were examined by means of optical and scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) analysis and hardness test, respectively. According to the microscopic investigations, no significant changes were observed after half an hour. However, results indicate that increasing time of homogenization leads to finer precipitations and a uniform distribution of them. The various cooling environments result in the formation of two types of precipitation phases. It was seen that in the high cooling rate, the majority of precipitations consisted of Ti2(Ni,Cu) while by decreasing cooling rate NiTiCu precipitates appeared too, which affect the hardness.

Microstructure, Mechanical Properties and Wear Resistance of Fe-Al Based Alloys with Various Alloying Elements

2004 ◽  
Vol 842 ◽  
Author(s):  
Han-Sol Kim ◽  
In-Dong Yeo ◽  
Tae-Yeub Ra ◽  
Won-Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Alloying Elements ◽  
Vacuum Arc ◽  
High Temperature Region ◽  
X Ray ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Zr Addition ◽  
Dendritic Structures

ABSTRACTWe report on microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements. The microstructures were examined using optical and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscope (EDS). Two types of alloys were prepared using vacuum arc melting; one is Fe-28Al based alloys (D03 structured) with and without alloying elements such as Mo and Zr. The other one is Fe-35Al based alloys (B2 structured) produced with same manner. For both types of alloys, equiaxed microstructures were observed by the addition of Mo, while dendritic structures were observed by the Zr addition. These microstructural features were more evinced with increasing the content of alloying elements. Concerning the mechanical properties and wear resistance, Fe-35Al based alloys with or without Mo addition superior to Fe-28Al based alloys especially in the high temperature region.

Effect of Mo and Ni Content on the Mechanical Properties of Low Carbon and Alloy Steel Casting Sample for Coal-Mining Machinery

2012 ◽  
Vol 476-478 ◽  
pp. 329-333
Author(s):  
Zhi Ying Ma ◽  
Yi Tao Yang
Keyword(s):  
Mechanical Properties ◽  
Melting Furnace ◽  
Vacuum Arc ◽  
Low Carbon ◽  
Alloy Casting ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Ni Content ◽  
Mining Machinery ◽  
Casting Steel

The effect of Mo and Ni content on the mechanical properties of low carbon and alloy casting steel by using Vacuum Arc Melting Furnace had been studied in this paper. The results indicated that increasing Mo or Ni content would enhance the hardness and strength of the steel separately, with some of elongation loss. It showed that ferrite refined with the increasing alloy content. The combinations of Mo and Ni content were of importance for comprehensive mechanical properties and wear resistance. The appropriate content in low carbon casting steel with 0.02%Nb was 0.5%-0.6%Mo and 0.2%-0.4%Ni.

Ti5Si3/β-Ti nano-core–shell structure toughened glassy Ti alloy matrix biocomposites

RSC Advances ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 8355-8361 ◽  
Author(s):  
Chunxiang Cui ◽  
Ling Bai ◽  
Shuangjin Liu ◽  
Yumin Qi ◽  
Lichen Zhao
Keyword(s):  
Shell Structure ◽  
Melting Furnace ◽  
Vacuum Arc ◽  
Core Shell ◽  
Ti Alloy ◽  
Alloy Matrix ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Core Shell Structure

In the experiment, Ti75Zr11Si9Fe5 and Ti66Zr11Si15Fe5Mo3 ingots were prepared by vacuum arc-melting furnace.

Fabrication and Properties of TiB2 Reinforced Cu Composites by Electromagnetic Stirring

2004 ◽  
Vol 449-452 ◽  
pp. 297-300 ◽  
Author(s):  
Taek Kyun Jung ◽  
Sung Chul Lim ◽  
Hyouk Chon Kwon ◽  
Mok Soon Kim
Keyword(s):  
Annealing Temperature ◽  
Volume Fraction ◽  
Melting Furnace ◽  
Electromagnetic Stirring ◽  
Vacuum Arc ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Copper Melt ◽  
Mean Size ◽  
The Mean

Cu-Ti and Cu-B alloys were separately cast in vacuum arc melting furnace for alloying. These alloys were added to the copper melt of 1500K in the induction furnace and performed electromagnetic stirring at 1000rpm. The cast ingot(dia : 70mm, length : 100mm) was hot extruded with the extrusion ratio of 13:1 after heating at 1073K for 1 hour. The TiB 2 precipitates were observed in the extruded materials and the mean size of TiB 2 precipitates was found to be about 1.5µm. The volume fraction of TiB 2 varies due to the density difference between the TiB2 and the copper melt. With the increasing of TiB2 contents from 3 to 8 vol.%, the hardness and the tensile strength increased from 951 to 140Hv and from 248 to 278MPa, respectively, and the electrical conductivity decreased from 82 to 70%IACS. However, the mean size of TiB 2 particle was not increased despite increasing an annealing temperature.

Electrochemical Properties of TiN and ZrN Coated Ti-Hf Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 813-816
Author(s):  
Yong Hoon Jeong ◽  
Han Cheol Choe ◽  
Su Jung Park ◽  
Yeong Mu Ko
Keyword(s):  
Electrochemical Properties ◽  
Melting Furnace ◽  
Alloy System ◽  
Rf Magnetron Sputtering ◽  
Vacuum Arc ◽  
Nacl Solution ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Layer Analysis ◽  
Coated Surface

The Ti-Hf alloy system forms α-β isomorphous system and does not form any intermetallic compounds, which is also beneficial for good mechanical properties. And in order to avoid the release of materials, surface modifications are generally carried out to form a TiN and ZrN layer on the surface. Electrochemical properties of TiN and ZrN coated Ti-Hf alloy by RFsputtering has been researched using various electrochemical methods. Ti-10wt%, 20wt%, 30wt%, and 40wt% Hf alloys manufactured by non consumable vacuum arc melting furnace. All the specimens were heat treatment at 1000°C for 24hr in Ar atmosphere followed by furnace cooling, respectively. The specimens were coated with TiN and ZrN respectively, by RF-magnetron sputtering method. The microstructures were conducted by using OM, EDX and SEM. The corrosion tests were carried out using potentiodynamic(PARSTAT 2273, EG&G, USA) and potentiostatic test in 0.9% NaCl solution at 36.5 ±1 °C. Microstructure clearly observed that lamellar structure translated to needle-like structure with increased Hf contents. From the analysis of TiN and ZrN coated layer analysis, TiN and ZrN coated surface showed columlar structure with 600nm and 100nm thickness, respectively. The corrosion resistance of TiN and ZrN coated Ti alloys were higher than those of the non-coated Ti-alloy in 0.9%NaCl solution, indicating better protective effect.

scholarly journals Microstructure and Oxidation Resistance of Cr–Al–Si Alloys for High-Temperature Applications

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 329
Author(s):  
Jeong-Min Kim ◽  
Chae-Young Kim
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Single Phase ◽  
Melting Furnace ◽  
Vacuum Arc ◽  
Coating Materials ◽  
Temperature Oxidation ◽  
Al Content ◽  
Arc Melting ◽  
Vacuum Arc Melting

Cr–Al alloys are attracting much attention as heat- and corrosion-resistant coating materials due to their excellent high-temperature properties. In order to investigate the effect of aluminum content on the microstructure and oxidation resistance of Cr–Al–Si alloys, cast specimens were prepared by using a vacuum-arc melting furnace, and high-temperature oxidation tests were conducted with the specimens, for 1 h, at 1100 °C, in air. In the case of cast microstructure of Cr–Al–Si alloys, it consists mainly of Cr single phase, up to 5 at.% Al, and AlCr phases were additionally formed in alloys containing 10% Al or more. In the specimen with 20% Al added, CrSi phase was also found in addition to the AlCr phase. The weight change of the specimens heated for 1 h, at 1100 °C, indicated that all had excellent oxidation resistance. However, when the Al content was less than 10%, the weight gain tended to be a little lower than that of 10% or more.

Preparation and Research of AuNi Cathode Catalyst for Direct Methanol Fuel Cell

2011 ◽  
Vol 130-134 ◽  
pp. 1039-1043
Author(s):  
Shao Hui Yan ◽  
Wei Li Zhu ◽  
Shi Chao Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Reduction Reaction ◽  
Vacuum Arc ◽  
Methanol Tolerance ◽  
X Ray ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Electrocatalytic Oxygen Reduction ◽  
Direct Methanol ◽  
Electron Reduction

AuNi alloy was synthesized by vacuum arc melting in high-purity argon atmosphere. The AuNi alloy was characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The results of EDS indicated that Au and Ni atoms were well-distributed in the alloy. Moreover, the results of XPS exhibited an electronic transfer from Ni to Au in AuNi phase. The Electrocatalytic oxygen reduction reaction (ORR) activity and the methanol tolerance of the AuNi alloy were respectively investigated using the RDE method and the electrochemical cyclic voltammetry. The results suggested that O2was directly oxidized to H2O on the AuNi catalyst via an approximate four-electron reduction pathway, and that the AuNi catalyst had a high electrocatalytic activity for the ORR and an acceptable methanol tolerance, simultaneously.

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