Effect of Reaction between Fe and Carbide Particles on Mechanical Properties of Fe-Base Composite

2008 ◽  
Vol 55-57 ◽  
pp. 357-360 ◽  
Author(s):  
S. Chakthin ◽  
Nuchthana Poolthong ◽  
Ruangdaj Tongsri

Sintered Fe-5 wt. % carbide (SiC or TiC) composites have been prepared via a powder metallurgy (P/M) route. Two carbide particle sizes, < 20 µm and 20-32 µm, were mixed with Fe powder. The powder mixtures were compacted and sintered at 3 different temperatures, 1100, 1150 and 1200 °C. Microstructures of sintered Fe-5 wt. % SiC composites showed evidence of SiC decomposition. The decomposed Si and C atoms diffused into Fe particles resulting in formation of solid solution of Si and C in Fe during sintering. During cooling, the solid solution of C in Fe decomposed to pearlite structure (ferrite and cementite (Fe3C) lamellar structure). Microstructures of sintered Fe-5 wt. % TiC composites showed no evidence of TiC decomposition at the investigated sintering temperatures. Because of the reaction between SiC and Fe, tensile strength and hardness of the sintered Fe-SiC composites were higher than those of the sintered Fe. Experimental results showed that strength and hardness of the sintered Fe-SiC composites increased with increasing sintering temperature and with decreasing SiC particle size. In contrast, mechanical properties of the sintered Fe-TiC composites were inferior to those of the sintered Fe. The reason of poor mechanical properties may be attributed to poor bonding between Fe and TiC particles.

Author(s):  
M. A. Salem ◽  
I. G. El-Batanony ◽  
M. Ghanem ◽  
Mohamed Ibrahim Abd ElAal

Different Al-SiC metal matrix composites (MMCs) with a different matrix, reinforcement sizes, and volume fractions were fabricated using ball milling (BM) and powder metallurgy (PM) techniques. Al and Al-SiC composites with different volume fractions were milled for 120 h. Then, the Al and Al-SiC composites were pressed under 125 MPa and finally sintered at 450 °C. Moreover, microsize and combination between micro and nano sizes Al-SiC samples were prepared by the same way. The effect of the Al matrix, SiC reinforcement sizes and the SiC volume fraction on the microstructure evolution, physical and mechanical properties of the produced composites was investigated. The BM and powder metallurgy techniques followed by sintering produce fully dense Al-SiC composite samples with different matrix and reinforcement sizes. The SiC particle size was observed to have a higher effect on the thermal conductivity, electrical resistivity, and microhardness of the produced composites than that of the SiC volume fraction. The decreasing of the Al and SiC particle sizes and increasing of the SiC volume fraction deteriorate the physical properties. On the other hand, the microhardness was enhanced with the decreasing of the Al, SiC particle sizes and the increasing of the SiC volume fraction.


2019 ◽  
Vol 38 (2019) ◽  
pp. 892-896 ◽  
Author(s):  
Süleyman Tekeli ◽  
Ijlal Simsek ◽  
Dogan Simsek ◽  
Dursun Ozyurek

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.


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. 


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.


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.


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.


2013 ◽  
Vol 457-458 ◽  
pp. 131-134 ◽  
Author(s):  
Tao Fan ◽  
Cong Li Xiao ◽  
Yan Rong Sun ◽  
Hong Bo Li

The aim of this study is to investigate the effect of SiC particle pretreatment, aluminum matrix particle size and sintering temperature on relative density, hardness, microstructure and wear resistance to SiC particle einforced aluminum matrix composites. To this end, the amount of 16.7 wt.% SiC with average particle sizes 20μm was used along with pure aluminum of average particle size of 75 μm and 25μm. Powder metallurgy is a method used in the fabrication of this composite in which the powders were mixed using a planetary ball mill. By analyzing SEM micrograph and the Property test, it is concluded that SiC particle pretreatment has significant effect on the morphology of pecimens. pretreatment increase the interface adhesion, improve the wettability. SiC is uniformly distributed in the matrix, with good relation to the substrate, the maximum hardness is 51.1HB, the minimum wear rate is 0.1684%, while the density is 97.3%.For the same SiC content and particle size, the smaller the particle size of aluminum matrix is, the higher wear resistance of composite materials is on condition that others are same, the higher sintering temperature and the higher the wearability of composites, the wear resistance of the composite material is significantly improved after SiC pre-processing.The relative density increases with increasing aluminum matrix particle sizes under the same pressure and the holding time. The actual density of all samples reached the theoretical density over 96%, to a maximum of 98.9%.


2017 ◽  
Vol 907 ◽  
pp. 3-7
Author(s):  
Hülya Akkan ◽  
Mehmet Şi̇mşi̇r ◽  
Kerim Emre Öksüz

NiTi shape memory alloys have attracted significant interest due to their unique superelasticity and high damping performance. In this work, the effect of SiC particle size on both physical and mechanical properties of NiTi matrix composite was investigated. Ni and Ti powders with particle sizes of 40 µm were used with the SiC addition with varying particle sizes of 20 µm and 40 µm, respectively. Composites of NiTi with 1wt. % SiC were fabricated by powder metallurgy technique. The effects of SiCp addition on hardness, relative density and wear behavior of NiTi composites have been investigated. The samples were examined by scanning electron microscope, for microstructural studies and phase development. The results showed that the distribution of the reinforced particle was uniform. Moreover, as the SiC particle size decreases, hardness and wear resistance increase. It was demonstrated that SiC particle size significantly enhanced the wear resistance of NiTi composite.


2000 ◽  
Vol 15 (11) ◽  
pp. 2314-2321 ◽  
Author(s):  
Noboru Yoshikawa ◽  
Singo Funahashi ◽  
Shoji Taniguchi ◽  
Atsushi Kikuchi

Al/Al2O3 composites were fabricated by a displacement reaction between SiO2 and molten Al. In this study, fabrication of Al/Al2O3 composites was attempted by means of reactive infiltration to provide variation of their mechanical properties. SiO2 preforms having various porosities and pore size distributions were prepared by sintering the powder at different temperatures between 1273 and 1723 K. Molten Al was infiltrated at 1373 K without application of pressure. Infiltration kinetics were studied and the microstructures of the composite bodies were observed by means of scanning electron microscopy (with energy dispersive x-ray microanalysis), wave dispersive x-ray microanalysis, and x-ray diffractions. The infiltrated specimens were mainly composed of Al and α–Al2O3 phases, and the Si content was less than 5 at.%. Volume fraction of Al phase in the composite bodies was not altered very much with the porosities of the SiO2 preforms because of the difficulty in filling out the entire pore space. Properties and microstructures of Al/Al2O3 composites, however, were dependent on the sintering temperature of the SiO2 preforms. In the case of low sintering temperature, a thick Al channel existed, which deformed upon compression. In the case of high sintering temperature, the microstructure became homogeneous and had thinner Al channels. The composite bodies became brittle. The deformation behavior was shown to be changed from ductile to brittle as an increase of the sintering temperature of the preforms.


2008 ◽  
Vol 1128 ◽  
Author(s):  
Mira Sakaliyska ◽  
Sergio Scudino ◽  
Hoang Viet Nguyen ◽  
Kumar Babu Surreddi ◽  
Birgit Bartusch ◽  
...  

AbstractNanostructured Al-Mg bulk samples with compositions in the range of 10 – 40 at.% Mg have been produced by consolidation of mechanical alloyed powders. Powders with composition Al90Mg10 and Al80Mg20 were consolidated into highly dense specimens by hot extrusion. Room temperature compression tests for the Al90Mg10 specimen reveal interesting mechanical properties, namely, a high strength of 630 MPa combined with a plastic strain of about 4 %. The increase of the Mg content to 20 at.% increases the strength by about 100 MPa but it suppresses plastic deformation. The Al60Mg40 powder was consolidated at different temperatures by spark plasma sintering and the effect of the sintering temperature on microstructure, density and hardness have been studied. The results reveal that both density and hardness of the consolidated samples increase with increasing sintering temperature, while retaining a nanocrystalline structure. These results indicate that powder metallurgy is a suitable processing route for the production of nanocrystalline Al-Mg alloys with promising mechanical properties.


Sign in / Sign up

Export Citation Format

Share Document