Effects of SiO2 Particles in Mechanical Properties of Iron Composite

2013 ◽  
Vol 465-466 ◽  
pp. 886-890
Author(s):  
Adibah Amir ◽  
Othman Mamat

Tronohs raw sand was converted into fine silica particles via a series of milling process. Addition of these fine particles into iron composite was found to modify its mechanical properties. The composite was prepared using powder metallurgy technique with varying percentage of silica particles; 5, 10, 15, 20 and 25wt%. The composites were sintered at three different temperatures; 1000° C, 1100° C and 1200° C to find the most suitable sintering temperature. Changes in density and hardness were observed. The results showed that composite consist of 20wt% silica particles and sintered at 1100° C exhibits best improvement.

2016 ◽  
Vol 857 ◽  
pp. 242-245
Author(s):  
Mohd Tajuddin Mohd Tajuddin ◽  
Shamsul Baharin Jamaludin

PM Co-Cr-Mo (F75) alloys are widely used in implants due to their mechanical properties, good wear resistance and as well as biocompatibility. Currently, they are fabricated by casting technique. In this present research, F75 was fabricated by powder metallurgy technique. The powder was mixed with 2 wt. % of stearic acid in order to form green body and compacted at 500 MPa. The effect of sintering temperature was investigated to observe its effect to the microstructure of F75 (Co-Cr-Mo). Samples were sintered for 2 hours at 2 different temperatures (1250°C and 1300°C) with 10°C/min in argon atmosphere. Physical properties such as density and porosity were obtained by Archimedes principle. Microstructure was observed by using optical microscope Olympus BX41M. The results indicate that increasing the sintering temperature will influence the density and porosity, thus the microstructure itself.


2021 ◽  
Vol 18 (23) ◽  
pp. 683
Author(s):  
Bappi Sarker ◽  
Md. Arafat Rahman ◽  
Md. Mizanur Rahman ◽  
Md. Saiful Islam

Despite the importance of Nickel Oxide (NiO) in diverse functional applications, very little information is available on the mechanical properties of bulk or porous NiO or, mostly unnoticed. In this study, porous Ni-NiO foam was synthesized using space holding-powder metallurgy and sintering methods to produce opened-cell structure with macrogravel and Neolamarckia cadamba (Cadamba flower) like surface morphology. Four different types of porous Ni-NiO with different pore diameter of 35.65 ± 12.77, 36.10 ± 8.85, 68.20 ±7.36 and 62.45 ± 17.48 µm were fabricated for evaluating the effect of porosity on the mechanical properties of bulk porous Ni-NiO foam. The mechanical properties such as bulk crushing force of as synthesized Ni-NiO foam with various porosities such as 20.55, 27.35, 27.85 and 28.82 % exhibited the average crushing load of 115.40, 39.95, 138.10 and 151.20 N, respectively. This study suggests that crushing load of Ni-NiO foam is not only depending on the porosity but also on the sintering temperature and crystallite sizes of NiO. HIGHLIGHTS Ni-NiO foam is synthesized using space holding-powder metallurgy and sintering methods Different pore diameter is fabricated for evaluating the effect of porosity on the mechanical properties of bulk porous Ni-NiO foam Crushing strength of Ni-NiO foam is not only depending on the porosity but also on the sintering temperature and crystallite sizes of NiO GRAPHICAL ABSTRACT


2020 ◽  
Vol 38 (3) ◽  
pp. 273-286 ◽  
Author(s):  
Cristina Garcia-Cabezon ◽  
Celia Garcia-Hernandez ◽  
Maria L. Rodriguez-Mendez ◽  
Gemma Herranz ◽  
Fernando Martin-Pedrosa

AbstractMicrostructural changes that result in relevant improvements in mechanical properties and electrochemical behavior can be induced using different sintering conditions of ASTM F75 cobalt alloys during their processing using powder metallurgy technique. It has been observed that the increase in carbon and nitrogen content improves corrosion resistance and mechanical properties as long as the precipitation of carbides and nitrides is avoided, thanks to the use of rapid cooling in water after the sintering stage. In addition, the reduction of the particle size of the powder improves hardness and resistance to corrosion in both acid medium with chlorides and phosphate-buffered medium that simulates the physiological conditions for its use as a biomaterial. These results lead to increased knowledge of the role of carbon and nitrogen content in the behavior displayed by the different alloys studied.


2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 


2021 ◽  
Vol 105 ◽  
pp. 8-16
Author(s):  
Guttikonda Manohar ◽  
Krishna Murari Pandey ◽  
Saikat Ranjan Maity

Metal matrix composites attain a significant position in Industrial, defense, structural and automobile applications. To amplify that strategy there is a need to find out the conditional behavior of the composites and enhancing the properties will be mandatory. The present work mainly investigates on the effect of processing parameters like densification rates, sintering temperature, reinforcement content on the microstructure, mechanical properties of the Al7175/B4C composite material fabricated by mechanical milling and powder metallurgy techniques. Results show there is a grain size reduction and refinement in the composite material through ball milling operations and along with that increasing B4C content in the composite powders make milling conditions very effective. Increasing the sintering temperature results in a consistent grain growth along with that porosity level decreases up to a limit and then attain a steady state, the strength of the composites increases with compaction pressures but reinforcements content effects the strength of the material by losing its ductility making it brittle.


2020 ◽  
Vol 10 (22) ◽  
pp. 8279
Author(s):  
Elisa Fiume ◽  
Gianpaolo Serino ◽  
Cristina Bignardi ◽  
Enrica Verné ◽  
Francesco Baino

The intrinsic brittleness of bioactive glasses (BGs) is one of the main barriers to the widespread use of three-dimensional porous BG-derived bone grafts (scaffolds) in clinical practice. Among all the available strategies for improving the mechanical properties of BG-based scaffolds, strut densification upon sintering treatments at high temperatures represents a relatively easy approach, but its implementation might lead to undesired and poorly predictable decrease in porosity, mass transport properties and bioactivity resulting from densification and devitrification phenomena occurring in the material upon heating. The aim of the present work was to investigate the sinter-crystallization of a highly bioactive SiO2-P2O5-CaO–MgO–Na2O–K2O glass (47.5B composition) in reference to its suitability for the fabrication of bonelike foams. The thermal behavior of 47.5B glass particles was investigated upon sintering at different temperatures in the range of 600–850 °C by means of combined thermal analyses (differential thermal analysis (DTA) and hot-stage microscopy (HSM)). Then, XRD measurements were carried out to identify crystalline phases developed upon sintering. Finally, porous scaffolds were produced by a foam replica method in order to evaluate the effect of the sintering temperature on the mechanical properties under compression loading conditions. Assessing a relationship between mechanical properties and sintering temperature, or in other words between scaffold performance and fabrication process, is a key step towards the rationale design of optimized scaffolds for tissue repair.


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3140 ◽  
Author(s):  
Zhun Cheng ◽  
Xiaoqiang Li ◽  
Minai Zhang ◽  
Shengguan Qu ◽  
Huiyun Li

In this study, K417G Ni-based superalloy with a 20-mm gap was successfully bonded at 1200 °C using powder metallurgy with a powder mixture. The results indicated that the microstructure and mechanical properties of the as-bonded alloy were highly dependent on the brazing time (15–45 min), mainly due to the precipitation and distribution characteristics of M3B2 boride particles. Specifically, alloy brazed for 30 min exhibited desirable mechanical properties, such as a high tensile ultimate strength of 971 MPa and an elongation at fracture of 6.5% at room temperature, exceeding the balance value (935 MPa) of the base metal. The excellent strength and plasticity were mainly due to coherent strengthening and dispersion strengthening of the in situ spherical and equiaxed M3B2 boride particles in the γ + γ′ matrix. In addition, the disappearance of dendrites and the homogenization of the microstructure are other factors that cannot be excluded. This powder metallurgy technique, which can avoid the eutectic transformation of traditional brazing, provides a new effective method for wide-gap repair of alloy materials.


2017 ◽  
Vol 863 ◽  
pp. 26-32
Author(s):  
Ming Zhou Su ◽  
Hui Meng Wang ◽  
Chang Chen

Porous irons with only micropores were produced through powder metallurgy route. Corn starch of small particle size (5-15μm) was utilized to regulate the densification of green compacts. The structural and mechanical properties of porous irons sintered at different temperatures were evaluated. The porosities increased with increasing the starch content, which reduced compressive strength and increased volumetric shrinkage. The compressive yield stress increased with increasing sintering temperature. It was also found that the effect of sintering temperature on the microstructure and compressive properties was more obvious when green compacts were less densified. Moreover, volumetric shrinkage of porous irons without adding starch remains in a quite low level for different sintering temperatures.


2011 ◽  
Vol 316-317 ◽  
pp. 97-106 ◽  
Author(s):  
Tahir Ahmad ◽  
Othman Mamat

Metal matrix-particulate composites fabricated by using powder metallurgy possess a higher dislocation density, a small sub-grain size and limited segregation of particles, which, when combined, result in superior mechanical properties. The present study aims to develop iron based silica sand nanoparticles composites with improved mechanical properties. An iron based silica sand nanoparticles composite with 5, 10, 15 and 20 wt.% of nanoparticles silica sand were developed through powder metallurgy technique. It was observed that by addition of silica sand nanoparticles with 20 wt.% increased the hardness up to 95HRB and tensile strength up to 690MPa. Sintered densities and electrical conductivity of the composites were improved with an optimum value of 15 wt.% silica sand nanoparticles. Proposed mechanism is due to diffusion of silica sand nanoparticles into porous sites of the composites.


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