Quantitative Evaluation of Interstitial Elements in the Processing of Ti-6Al-4V Alloy by Powder Metallurgy

2012 ◽  
Vol 727-728 ◽  
pp. 374-379 ◽  
Author(s):  
S.L.G. Petroni ◽  
V.A.R. Henriques ◽  
M.S.M. Paula ◽  
C.A.A. Cairo
Keyword(s):  
Powder Metallurgy ◽  
Titanium Hydride ◽  
Titanium Powder ◽  
Milling Time ◽  
Sintering Temperature ◽  
Low Cost ◽  
High Reactivity ◽  
Holding Time ◽  
Carbon Absorption ◽  
Interstitial Elements

The use of hydride powders in titanium powder metallurgy (P/M) is a low cost alternative for the manufacture of titanium alloys. However, due to the high reactivity of these powders, parts produced using this technique may contain interstitial impurities such as oxygen, nitrogen and carbon. In this work a factorial design approach was used to evaluate the influence of some stages of P/M upon the levels of these elements in sintered samples of Ti-6Al-4V. Milling time of titanium hydride powders, sintering temperature and holding time were evaluated. The effect of milling time was detected as the most significant for the increase in oxygen levels. The contents of all elements were affected by the increase of sintering temperature from 1200 °C to 1400 °C. Holding time was shown to be significant only for the carbon absorption in the samples sintered at 1400 °C.

scholarly journals The effect of milling time on the alumina phase transformation in the AMCs powder metallurgy reinforced by silica-sand-tailings

2022 ◽  
pp. 103-117
Author(s):  
Sukanto ◽  
Wahyono Suprapto ◽  
Rudy Soenoko ◽  
Yudy Surya Irawan
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Powder Metallurgy ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Sintering Temperature ◽  
Silica Sand ◽  
Second Phase ◽  
The Matrix ◽  
The Impact

This study aims to determine the effect of milling time and sintering temperature parameters on the alumina transformation phase in the manufacture of Aluminium Matrix Composites (AMCs) reinforced by 20 % silica sand tailings using powder metallurgy technology. The matrix and fillers use waste to make the composites more efficient, clean the environment, and increase waste utilization. The milling time applied to the Mechanical Alloying (MA) process was 0.5, 6, 24, 48, and 96 hours, with a ball parameter ratio of 15:1 and a rotation of 93 rpm. Furthermore, hot compaction was carried out using a 100 MPa two-way hydraulic compression machine at a temperature of 300 °C for 20 minutes. The temperature variables of the sintering parameter process were 550, 600 to 650 °C, with a holding time of 10 minutes. Characterization of materials carried out included testing particle size, porosity, X-Ray Diffraction (XRD), SEM-Image, and SEM-EDX. The particle measurement of mechanical alloying processed, using Particle Size Analyzer (PSA) instrument and based on XRD data using the Scherrer equation, showed a relatively similar trend, decreasing particle size occurs when milling time was increased 0.5 to 24 hours. However, when the milling time increases to 48 and 96 hours, the particle size tends to increase slightly, due to cold-weld and agglomeration when the Mechanical Alloying is processed. The impact is the occurrence of the matrix and filler particle pairs in the cold-weld state. So, the results of XRD and SEM-EDX characterization showed a second phase transformation to form alumina compounds at a relatively low sintering temperature of 600 °C after the mechanical alloying process was carried out with a milling time on least 24 hours

Graphite/Copper Composites with High Density

2015 ◽  
Vol 723 ◽  
pp. 475-480 ◽  
Author(s):  
Yong Ping Jin ◽  
Bin Guo
Keyword(s):  
Electron Microscope ◽  
Powder Metallurgy ◽  
Relative Density ◽  
Milling Time ◽  
Sintering Temperature ◽  
Optical Microscope ◽  
Difficult Problem ◽  
Copper Compound ◽  
Technological Parameters ◽  
Scanning Electron

It is a difficult problem how to obtain the density of powder metallurgy products. Sintering billets had been prepared by mechanical milled graphite/copper compound powders firstly. Their microstructures had been analyzed by such means as scanning electron microscope (SEM) and optical microscope. Influence of technological parameters on relative density had also been investigated. The results show that sintering of non-milled powders are intensely affected by sintering temperature, contrary to mechanical milled compound powders. Hot pressed sintering under vacuum can promote densification effectively. By prolonging time, elevating temperature or pressure of hot pressed sintering, relative density of sintering billets can be increased accordingly. Under the same conditions, relative density decreases with mechanical milling time of compound powders.

Densification Behaviors of Fe-TiC System during Spark Plasma Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 509-512 ◽  
Author(s):  
Yong-Hee Lee ◽  
Dong Kyu Park ◽  
Sung Yeal Bea ◽  
In Sup Ahn
Keyword(s):  
Sintering Temperature ◽  
Low Cost ◽  
Cost Effective ◽  
Mass Effect ◽  
Liquid Pool ◽  
Holding Time ◽  
High Mass ◽  
Sintering Time ◽  
Conventional Sintering ◽  
Light Material

The SPS process is a synthetic technique which enables sinter-bonding to occur at low temperature and within a short sintering time. Furthermore, it produces finer grain size than conventional sintering methods. Fe-TiC system is a relatively light material and is one third the size of tungsten carbide and less than half weight of tool steel. It is cost effective when used in Fe-TiC system due to high mass effect with low density and relatively low cost of changing tools and bearings. Fe-TiC system can be machined easily with conventional equipment. In the present work, SPS was conducted at the temperatures of 1200, 1250 and 1300°C at the sintering time of 3, 5 and 10min. As the sintering temperature and holding time increased, the relative density decreased and the hardness reached the lowest at 1250°C. These are attributed to the more pore being generated by liquid Pool at 1250°C and 1300°C. The result of the microstracture observation showed more M6C and MC carbide by liquid Pool as sintering temperature and holding time increased.

Development of Titanium Dental Implants Using Techniques of Powder Metallurgy

2014 ◽  
Vol 775-776 ◽  
pp. 13-18 ◽  
Author(s):  
Pâmela Karina dos Santos Bonfim ◽  
Ricardo Ciuccio ◽  
Maurício David Martins das Neves
Keyword(s):  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Biomedical Applications ◽  
Titanium Powder ◽  
Pure Titanium ◽  
High Reactivity ◽  
Titanium Implants ◽  
Vacuum Sintering ◽  
High Mechanical Strength ◽  
Titanium Dental Implants

Titanium is an attractive material for dental and biomedical applications, because of high corrosion resistance, excellent biocompatibility and high mechanical strength combined with low density. However, the high reactivity of titanium in the liquid phase make it difficult to produce it by fusion, so a alternative is powder metallurgy (P/M) method. Powder Metallurgy has been used to manufacture porous implants. The presence of a porous surface is desirable because it improves the osteointegration increases the adhesion between the bone tissue and the implant, being favorable for transporting body fluid. This paper proposes to characterize the commercial pure titanium powder obtained by process of hydride-dehydride, obtain samples with adequate porosity by uniaxial pressing and vacuum sintering and evaluate the corrosion behavior of sintered titanium in Hank ́s solution. The results showed that the titanium powder of angular shape after uniaxial pressing of 400 MPa and sintered in vacuum at 1150 ° C, allowed obtaining samples with adequate surface porosity of around 17%. In potentiodynamic polarization curves revealed no typical behavior of passive metals but show low current density, that increasing corrosion resistance. Keywords: titanium implants, powder metallurgy, porosity and electrochemical behavior.

Hardness, Density and Porosity of Al/(SiCw+Al2O3p) Composite by Powder Metallurgy Process without and with Sintering

2015 ◽  
Vol 776 ◽  
pp. 246-252 ◽  
Author(s):  
Ketut Suarsana ◽  
Rudy Soenoko
Keyword(s):  
Powder Metallurgy ◽  
Test Specimen ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Holding Time ◽  
Sintering Process ◽  
Interface Bonding ◽  
Powder Metallurgy Process ◽  
Metallurgy Process

Al/(SiCw+Al2O3p) composite was a blend of fine aluminum powder serving as a matrix while Silicon Carbid whiskers (SiCw) and Alumina (Al2O3p) as a reinforcement. Powder metallurgy was used for the manufacture of composites according to the shape of the test specimen. Parameter testing was conducted with varied sintering holding time of 1 h, 3 h and 6 h at a sintering temperature of 500°C and 600°C. This study was conducted to know hardness properties, density, porosity and SEM analysis. The results show that the sintering process which has been conducted affects the physical and mechanical properties of the composite. Increased hardness and density occur due to the stronger or more dense interface bonding between matrix and reinforcement which are affected by the increase in the holding time and sintering temprature, where the highest is at 6 hours with 600°C, while the porosity decreases inversely proportional to the density and the hardness that occur in composite materials.

Study about the Influence of Two-Steps Sintering (TTS) Route for an Alloy Based on Titanium

2018 ◽  
Vol 880 ◽  
pp. 256-261
Author(s):  
Cristina Ileana Pascu ◽  
Stefan Gheorghe ◽  
Daniela Florentina Tărâţă ◽  
Claudiu Nicolicescu ◽  
Cosmin Mihai Miriţoiu
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Titanium Hydride ◽  
Low Cost ◽  
Ti Alloy ◽  
Metallic Powders ◽  
Titanium Hydride Powder ◽  
Hydride Powder

This paper describes the influence of two-steps sintering regime temperatures concerning the final properties of titanium hydride based alloy obtaining by Two-Steps Sintering (TTS) route, which is a method that is part of the Powder Metallurgy (PM) technology. The initial titanium hydride powder has been mixed with some metallic powders as: Alumix, Mn, Zr, Sn and graphite was added in different proportions for improving the final mechanical properties. The Two-Steps Sintering (TTS) route have been applied for obtaining a low-cost Ti- alloy. The effect of the sintering regime temperatures on the height and diameter shrinkages and density for these alloys based on titanium hydride powder was studied

scholarly journals Thermodynamic Investigation of Titanium Hydride Formation from Reduction of Titanium (Ⅳ) Chloride with Magnesium Hydride in Presence of Hydrogen Atmosphere

2020 ◽  
Vol 321 ◽  
pp. 07014
Author(s):  
Mohammad Rezaei Ardani ◽  
Ahmad Fauzi Mohd Noor ◽  
Sheikh Abdul Rezan Sheikh Abdul Hamid ◽  
Abdul Rahman Mohamed ◽  
Hooi Ling Lee ◽  
...  
Keyword(s):  
Reaction Time ◽  
Low Temperature ◽  
Titanium Hydride ◽  
Titanium Powder ◽  
Milling Time ◽  
Reduction Process ◽  
Hydrogen Atmosphere ◽  
Major Product ◽  
X Ray ◽  
Ball Milling Time

Thermodynamic assessment and experimental investigation for formation of titanium hydride (TiH2) from reduction of titanium tetrachloride (TiCl4) with magnesium hydride (MgH2) were carried out under hydrogen atmosphere. In this method, TiH2 production at low temperature was investigated, which can be used for further dehydrogenation process in titanium powder metallurgy. The effects of temperature, time, amount of titanium trifluoride (TiF3) as catalyst, and ball milling time of MgH2 on reduction process were evaluated. The range of each parameters were set to 250-350°C for temperature, 2-4 hr for reaction time, 4-10 wt% for TiF3, and 1-2 hr for ball milling time. The phase transformations after reduction process were studied by X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analyziz. The morphology of powders was analyzed by scanning electron microscope (SEM). The results showed that titanium trichloride (TiCl3) was formed as major product in experiments for the above conditions. However, with increasing the reaction time above 10hr, characterization study of the final products confirmed the formation of TiH2 as major product. Our findings indicated that producing of TiH2 from reduction of TiCl4 with MgH2 at low temperature was feasible and could lead to low cost synthesis method for TiH2 for titanium powder production.

scholarly journals Microstructure Evolution and Properties of an In-Situ Nano-Gd2O3/Cu Composite by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5021
Author(s):  
Haiyao Cao ◽  
Zaiji Zhan ◽  
Xiangzhe Lv
Keyword(s):  
Tensile Strength ◽  
Powder Metallurgy ◽  
Load Transfer ◽  
Sintering Temperature ◽  
Copper Matrix ◽  
Processing Parameters ◽  
Holding Time ◽  
Matrix Composites ◽  
Transmission Electron ◽  
Mean Size

Gadolinia (Gd2O3) is potentially attractive as a dispersive phase for copper matrix composites due to its excellent thermodynamic stability. In this paper, a series of 1.5 vol% nano-Gd2O3/Cu composites were prepared via an internal oxidation method followed by powder metallurgy in the temperature range of 1123–1223 K with a holding time of 5–60 min. The effects of processing parameters on the microstructure and properties of the composites were analyzed. The results showed that the tensile strength and conductivity of the nano-Gd2O3/Cu composite have a strong link with the microporosity and grain size, while the microstructure of the composite was determined by the sintering temperature and holding time. The optimal sintering temperature and holding time for the composite were 1173 K and 30 min, respectively, under which a maximum ultimate tensile strength of 317 MPa was obtained, and the conductivity was 96.8% IACS. Transmission electron microscopy observations indicated that nano-Gd2O3 particles with a mean size of 76 nm formed a semi-coherent interface with the copper matrix. In the nano-Gd2O3/Cu composite, grain-boundary strengthening, Orowan strengthening, thermal mismatch strengthening, and load transfer strengthening mechanisms occurred simultaneously.

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