Characterization of Ti-27Nb-13Zr Alloy Produced by Powder Metallurgy

2012 ◽  
Vol 77 ◽  
pp. 178-183
Author(s):  
Marcio W.D. Mendes ◽  
Ana Helena Almeida Bressiani ◽  
José Carlos Bressiani

Titanium alloy are widely used in biomedical applications due to their excellent properties such as high strength, good corrosion resistance and excellent biocompatibility. Researches are being developed with elements such as Nb and Zr that reach all criterions for excellent biocompatibility and provide titanium alloys with Young’s modulus close to human bone. The aim of this work was to produce Ti-27Nb-13Zr alloy with different milling times by powder metallurgy process. The mixtures were performed by high energy milling and sintering in high vacuum furnace with temperature of 1300 °C / 3 h. The microstructures of samples were analyzed by SEM and XRD, while the mechanical behavior was evaluated by elastic modulus and Vickers hardness test. The diffraction results of sintering treatment indicate that the alloys are composed of α and β phases. Images obtained by SEM indicate the formation of equiaxial structures. Vickers hardness measurements from sintered samples with 1300 °C / 3 h indicate mean values around 413, 473 and 609 HV for 2, 6 and 10 hours of milling, respectively. The values of elastic modulus enable use the alloy as biomaterial.

2010 ◽  
Vol 660-661 ◽  
pp. 176-181
Author(s):  
José Hélio Duvaizem ◽  
Gabriel Souza Galdino ◽  
Ana Helena A. Bressiani ◽  
Rubens Nunes de Faria Jr. ◽  
Hidetoshi Takiishi

The effects of the hydrogenation stage on microstructure and mechanical properties of Ti-13Nb-13Zr alloy produced by powder metallurgy have been studied. Powder alloys have been produced by hydrogenation with 250 MPa or 1 GPa and via high energy planetary ball milling. Samples were isostatically pressed at 200 MPa and sintered at 1150 °C for 7, 10 and 13 hours. Elastic modulus and microhardness were determined using a dynamic mechanical analyzer (DMA) and a Vickers microhardness tester. Density of the samples was measured using a liquid displacement system. Microstructure and phases presents were analyzed employing scanning electron microscopy (SEM). Elastic modulus was 81.3  0.8 and 62.6  0.6 GPa for samples produced by 250 MPa and 1 GPa hydrogenation, respectively when sintered for 7h.


2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040031
Author(s):  
Stella Raynova ◽  
Khaled Alsharedah ◽  
Fei Yang ◽  
Leandro Bolzoni

A powder metallurgy approach was applied for the synthesis of an [Formula: see text] Ti-2Al-3Fe alloy. Blends of the elemental Ti, Al and Fe powders were compacted and subsequently sintered. High-frequency induction heating (HFIH) instead of conventional high-vacuum furnace heating was used for the sintering, due to its high efficiency. The effect of temperature on the level of densification, residual porosity and mechanical properties was studied. Electron dispersive spectrum analysis was used to study the dissolution and homogenization of the alloying elements. The results showed that a short induction sintering (IS) cycle in the range of 10–15 min is sufficient to achieve significant powder consolidation, evident by the increase of the density and mechanical properties. The residual porosity diminishes with the increase of the sintering temperature. Full dissolution of the alloying powders is completed after sintering at temperatures above those of [Formula: see text]- to [Formula: see text]-phase transformation.


2012 ◽  
Vol 529-530 ◽  
pp. 574-579
Author(s):  
Tamiye Simone Goia ◽  
Kalan Bastos Violin ◽  
José Carlos Bressiani ◽  
Ana Helena de Almeida Bressiani

Titanium and its alloys are the main metals studied as porous metallic implants by their excellent mechanical properties and biological interactions. Production methods of porous metallic materials are based on powder metallurgy (PM), because it allows the manufacturing of parts with complex shapes and dimensions close to the finals (near-net shape), and the addition of alloying elements reaching a satisfactory structural homogeneity, and porosity. The pore production by space-holder technique constitutes of mixing organic compounds with metal powder, which when removed by thermal treatment prior structures are kept in place. The objective of this study is to obtain porous implants of commercially pure titanium (cpTi) and Ti-13Nb-13Zr alloy by PM with space-holder technique and albumin as an additive. For the processing of the samples were used hydride titanium powder (TiH2) to obtain cpTi samples, and metal powders of Ti, Nb and Zr in the stoichiometric proportions for obtaining the alloy samples. The samples were prepared by mixing the metallic powder to the albumin (30wt%) and filling a silicone model that was pressed isostatically (140 MPa). The thermal treatment was performed in an oxidizing atmosphere (350°C/1h) for the decomposition of organic material. The sintering was performed at a temperature of 1300°C (1h/cpTi, 3h/Alloy) in high vacuum furnace (10-5 mBar) to all samples. The calculated porosity showed a significant difference between the samples cpTi (40%) and alloy (60%). The samples surface characterization showed very rough with high specific surface area. Samples of cpTi presented formation of necks arising from sintering. In the alloy samples were observed homogenous microstructure with the presence of α and β phases composing the Widmanstätten structure. It is possible to conclude that the same amount albumin allowed the formation of pores in the microstructure of cpTi and alloy although in different proportions, without harming the sintering of both and allowing diffusion of the alloy elements.


2014 ◽  
Vol 802 ◽  
pp. 457-461 ◽  
Author(s):  
José Hélio Duvaizem ◽  
N.M.F. Mendes ◽  
J.C.S. Casini ◽  
A.H. Bressiani ◽  
H. Takiishi

Ti-13Nb-13Zr alloy produced via powder metallurgy was submitted to heat treatment under various conditions and the effects on microstructure and elastic modulus were investigated. Heat treatment was performed using temperatures above and below α/β transus combined with different cooling rates – furnace cooling and water quenching. Microstructure and phases were analyzed employing scanning electron microscopy and X-ray diffraction. Elastic Modulus was determined using a dynamic mechanical analyzer (DMA). The results indicated that α phase precipitation and elastic modulus values increased after heat treatment performed using temperature below α/β transus. However, when it was performed above α/β transus and using higher cooling rate, a decrease in elastic modulus was observed despite higher α phase precipitation, indicating that the microstructural modifications observed via SEM, due to the presence of martensitic α phase, influenced on elastic modulus values.


2020 ◽  
Vol 26 (4) ◽  
pp. 392-400
Author(s):  
Sankar CHINTHAMANI ◽  
Gangatharan KANNAN ◽  
Glan Devadhas GEORGE ◽  
Christopher Ezhil Singh SREEDHARAN ◽  
Krishna Sharma RAJAGOPAL

In this present study, the particle size of as received magnesium alloy (AZ91) and B4C powders was reduced through high energy ball mills. The combination of AZ91 (both 10 µm and 60 µm) reinforced with nano B4C particles were fabricated by powder metallurgy technique. The incorporation of nano B4C particles to the Mg matrix was done at various weight % such as 5, 10, 15 and 20. The AZ91 composites were fabricated in a suitable die set assembly and the green compacts were sintered in an electric muffle furnace at 500 °C with argon atmosphere for a dwell time of 1 h. The density of the composites was estimated using Archimedes principle. Micro hardness test was carried out for the prepared specimens and dry sliding wear test was conducted by using pin-on-disc apparatus at room temperature with varying loads and sliding velocities by keeping a constant Sliding Distance (SD). Among the various specimens, the composite with 10 µm size attained a higher Vickers hardness value as well as better wear resistant property. Worn surface analysis of the prepared composites was studied using Scanning Electron Microscope (SEM).


Author(s):  
S. Rajeshkannan ◽  
I. Manikandan ◽  
M. Vigneshkumar

Semiconductors like ZnS, TiO2 and BaTiO3 were reinforced with Al-Al2O3 Metal Matrix Composites (MMCs) and were made through powder metallurgy in order to have high strength, high hardness and good thermal conductivity compared with conventional materials. Three MMC of test specimens were prepared with varying reinforcement ratio Al-Al2O3-ZnS(94-5-1), Al-Al2O3-TiO2(94-5-1), Al-Al2O3-BaTiO3(94-5-1) percentage by weight respectively. The hardness test has been made by using Brinell hardness testing instrument. Hardness test revealed that the addition of reinforcement TiO2, BaTiO3 increases the hardness value. However, the addition of ZnS to the Al-Al2O3 MMCs showed decrease in the hardness value. The crystal structure of the 3 composites were examined through X-Ray Diffraction (XRD) peaks.


2011 ◽  
Vol 264-265 ◽  
pp. 748-753 ◽  
Author(s):  
A.R. Fatimah Azreen ◽  
Agus Geter E. Sutjipto ◽  
Erry Yulian Triblas Adesta

Copper-based composite now is a potential material for various applications, while powder metallurgy processing technique is an alternative for high temperature processing materials and net shape component. In this research, Cu-based composite containing 10-50 vol% SiC fibers was fabricated by employing the powder metallurgy route. The mixtures of SiC fibers and Cu particles were blended in a ball milling machine with the addition of ethanol at 150rpm. Then, the mixtures were uniaxially compacted into a ɸ13.5mm cylindrical pallet and followed by sintering in vacuum furnace from 800-950°C for 4 hours. The density of the composite decrease with increasing SiCf and density as high as 87% for 10vol% SiCf/Cu matrix sintered at 800°C had been achieved. The Vickers hardness of 774MPa also had been achieved for 10vol% SiCf/Cu matrix but sintered at 900°C.


2017 ◽  
Vol 899 ◽  
pp. 389-394
Author(s):  
Narayanna Marques Ferreira Mendes ◽  
Marcio W.D. Mendes ◽  
Ana Helena de Almeida Bressiani ◽  
Hidetoshi Takiishi

The effects of the heat treatment on the phase transformations, microstructures and mechanical properties of Ti-8.5Nb-4.5Ta-13Zr alloy were studies in this work. Some of the starting powder were obtained by hydrogenation method and homogenized with metallic tantalum in a high-energy planetary mill. The samples were compacted in a uniaxial and cold isostatic presses and then, sintered at 1150 °C for 10 hours under high vacuum. The heat treatments were carried out at the same sintering temperature, above the α / β transus, at different cooling rates such as furnace cooling, air cooling and water quenching. The sintered samples were characterized using the Archimedes density method, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The microhardness was measured using the Vickers indentation (ASTM E384-11 Standard). It was shown that the microstructure of Ti-8.5Nb-4.5Ta-13Zr alloy consists of beta-phase matrix and alpha-phase region of two structures: equiaxed and needle-like grains also known as Widmanstätten structure. The precipitation of the alpha-phase in the beta-phase matrix led to an increase in Vickers microhardness of the alloy which was furnace cooled. Moreover, a few remaining pores were still found and density above 98% was achieved.


2006 ◽  
Vol 15-17 ◽  
pp. 71-76 ◽  
Author(s):  
A. Nouri ◽  
X.B. Chen ◽  
Peter D. Hodgson ◽  
Cui E Wen

Various types of titanium alloys with high strength and low elastic modulus and, at the same time, vanadium and aluminium free have been developed as surgical biomaterials in recent years. Moreover, porous metals are promising hard tissue implants in orthopaedic and dentistry, where they mimic the porous structure and the low elastic modulus of natural bone. In the present study, new biocompatible Ti-based alloy foams with approximate relative densities of 0.4, in which Sn and Nb were added as alloying metals, were synthesised through powder metallurgy method. The new alloys were prepared by mechanical alloying and subsequently sintered at high temperature using a vacuum furnace. The characteristics and the processability of the ball milled powders and the new porous titanium-based alloys were characterised by X-ray diffraction, optical microscopy and scanning electron microscopy .The mechanical properties of the new titanium alloys were examined by Vickers microhardness measurements and compression testing.


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